Conduit fitting with components adapted for facilitating assembly

ABSTRACT

A fitting includes first and second threaded fitting components, a conduit gripping device, and a stroke resisting member having a first axial length, the stroke resisting member being disposed between a threaded portion of the first fitting component and a radially extending portion of the second fitting component. The stroke resisting member is axially engaged by the radially extending portion of the second fitting component when the first and second fitting components are joined together to a first relative axial position, such that a tightening torque beyond the first relative axial position is increased by the axial engagement. The stroke resisting member is plastically compressed to a second axial length smaller than the first axial length when the first and second fitting components are joined together to a second relative axial position advanced beyond the first relative axial position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and all benefit of U.S. ProvisionalPatent Application Ser. No. 61/990,822, filed on May 9, 2014, forFERRULE CARTRIDGE ASSEMBLY FOR CONDUIT FITTING, U.S. Provisional PatentApplication Ser. No. 61/990,823, filed on May 9, 2014, for CONDUITFITTING WITH TORQUE COLLAR INTEGRAL WITH NUT AND OPTIONAL CARTRIDGEFERRULES, and U.S. Provisional Patent Application Ser. No. 62/007,441,filed on Jun. 4, 2014, for CONDUIT FITTING WITH ASSEMBLY BY TORQUE USINGFERRULES, the entire disclosures of each of which are fully incorporatedherein by reference.

TECHNICAL FIELD OF THE INVENTIONS

The present disclosure relates to fittings for metal conduits such asmetal tube and pipe. More particularly, the disclosure relates tofittings that provide conduit grip and seal by tightening togethermating threaded fitting components. One example of a conduit fitting isa flareless fitting that uses one or more conduit gripping devices toestablish conduit grip and seal.

BACKGROUND OF THE DISCLOSURE

Conduit fittings are used in gas or liquid fluid systems to provide afluid tight mechanical connection between a conduit and another fluidflow device, such as another conduit, a flow control device such as avalve or regulator, a port and so on. A particular type of conduitfitting commonly used is known as a flareless fitting that uses one ormore conduit gripping devices such as ferrules, for example, to providethe grip and seal functions. Such fittings are popular as they do notrequire much preparation of the conduit end, other than squaring off andde-burring. We use the term “fitting” herein as a shorthand reference toa conduit fitting, such as a tube or pipe fitting, for example.

Other fittings, however, will be of interest for use with the presentinventions, including any fitting design that is assembled by tighteningtogether two mating threaded fitting components.

A conventional ferrule type fitting is pulled-up by turns, meaning thatthe threadably mating fitting components are tightened together aspecified number of relative turns and partial relative turns withrespect to each other past a reference position. The reference positionis often a finger tight position. By controlling the number of turns andpartial turns past the finger tight position, the relative stroke oraxial advance of the fitting components together may be controlled toassure that the ferrules effectively grip and seal the conduit.Oftentimes, such fittings are loosened for various repair andmaintenance activities in the fluid system, and then the loosenedfitting is re-tightened, commonly referred to as “remake” or “remaking”the fitting. Such remakes may be done with the same fitting componentsand ferrules, or sometimes one or more parts are replaced.

SUMMARY OF THE DISCLOSURE

An exemplary inventive concept provides a stroke resisting member thatis associated with a threaded fitting component for conduit. In anembodiment, the stroke resisting member may be formed integral with thethreaded fitting component to provide a one piece or unitary part. Thestroke resisting member comprises a structure that deforms when thestroke resisting member is axially loaded or compressed. Additionalembodiments are disclosed herein.

Another exemplary inventive concept provides a stroke resisting memberthat is associated with a threaded fitting component. In an embodiment,the stroke resisting member may be formed non-integral with the threadedfitting component to provide a two piece assembly. The stroke resistingmember comprises a structure that deforms when the stroke resistingmember is axially loaded or compressed. Additional embodiments aredisclosed herein.

Another exemplary inventive concept provides a stroke resisting memberthat is associated with a threaded fitting component. In an embodiment,the stroke resisting member may be formed non-integral with the threadedfitting component to provide a two piece assembly, with the strokeresisting member being attachable or cartridged to the threaded fittingcomponent. Additional embodiments are disclosed herein.

Another exemplary inventive concept provides a stroke resisting memberthat functions as a gauging feature, so that the stroke resisting membergauges the pull-up condition of a conduit fitting. In an embodiment, thestroke resisting member comprises a structure that deforms when thestroke resisting member is axially loaded or compressed. The strokeresisting member may be used to gauge an initial pull-up as well aspull-up for one or more remakes of the fitting. The gauging feature maybe used for pull-up by torque, or turns, or both. The gauging featuremay be used with threaded fittings and non-threaded fittings, and may beused with all metal fittings and fittings that are not all metal.Additional embodiments are disclosed herein.

Another exemplary inventive concept provides a threaded fittingcomponent that is a first threaded fitting component that threadablymates with a second threaded fitting component, and a stroke resistingmember, said stroke resisting member comprises a structure thatplastically deforms when the stroke resisting member is loaded orcompressed axially, the stroke resisting member having a first axiallength at a first relative axial position between said first threadedfitting component and said second threaded fitting component, and asecond axial length at a second relative axial position between saidfirst threaded fitting component and said second threaded fittingcomponent, wherein said first axial length and the second axial lengthare different. Additional embodiments are disclosed herein.

Another exemplary inventive concept that is presented herein provides asubassembly for a conduit fitting including first and second ferrulesalignable relative to an axis. The first ferrule includes a cammingsurface at a back portion thereof, and the second ferrule includes asurface that contacts the camming surface when the first ferrule and thesecond ferrule are axially moved together along the axis. Thesubassembly further includes a retaining structure that retains thefirst ferrule and the second ferrule together as a subassembly, with theretaining structure including a member at a rearward portion of thefirst ferrule; the member including a wall that delimits a recess, withthe second ferrule including a portion that is disposed in the recess.The wall includes a portion that is acute relative to the axis in aforward direction. Additional embodiments are disclosed herein.

Another exemplary inventive concept that is presented herein provides aferrule including a unitary body with a bore therethrough along an axis,and a member that extends from a back portion of the body. The memberincludes a web and a hook, and a wall that forms part of the web and thehook, with the wall, the web and the hook delimiting a recess, and thehook and the web being joined by a portion of the wall that forms ahinge. The hook includes a camming surface extending rearward andradially outward from an axially extending radially inward end portion,the camming surface being angled with respect to the radially inward endportion. Additional embodiments are disclosed herein.

Another exemplary inventive concept that is presented herein provides asubassembly for a conduit fitting, including first and second ferrulesalignable relative to an axis, and a retaining structure that retainsthe first ferrule and the second ferrule together as a subassembly. Theretaining structure includes a member at a back portion of the firstferrule. The member includes a web, a hook, and a wall that forms partof the web and the hook and delimits a recess. The second ferruleincludes a portion that is disposed in the recess. The wall includes ahinge or crease that joins the hook to the web, the wall furtherincluding a portion that is acute in a forward or inboard directionrelative to the axis. Additional embodiments are disclosed herein.

Another exemplary inventive concept that is presented herein provides asubassembly for a conduit fitting, including first and second ferrulesalignable relative to an axis, and a retaining structure that retainsthe first ferrule and the second ferrule together as a subassembly. Theretaining structure includes a member at a back portion of the firstferrule, the member including a web, a hook, and a wall that forms partof the web and the hook and delimits a recess. The second ferruleincludes a portion that is received in the recess when the first ferruleand the second ferrule are retained together. The wall includes a hingeor crease that joins the hook to the web, with the hook being deformedor bent in a forward or inboard direction relative to a radial line fromthe axis. Additional embodiments are disclosed herein.

Another exemplary inventive concept that is presented herein provides amethod of cartridging first and second ferrules as a discontinuouspreassembly. In the exemplary method, a first ferrule is provided havinga rearward extending retaining member defining an inner radial recess,with the retaining member including a radially inward extension defininga rearward facing camming surface. A second ferrule is aligned with thefirst ferrule along a common central axis. The second ferrule is axiallypressed against the first ferrule such that a radially outwardprojection of the second ferrule engages the camming surface of theretaining member to axially deform and radially expand the radiallyinward extension, thereby receiving the second ferrule projection in theinner radial recess. At least one of the axial deformation and theradial expansion of the radially inward extension is at least partiallyelastic, such that the radially inward extension snaps into a secondferrule retaining condition after the second ferrule projection isreceived in the inner radial recess. Additional embodiments aredisclosed herein.

Another exemplary inventive concept that is presented herein provides aferrule including a unitary body with a bore therethrough along an axisand a member that extends from a back portion of the body. The memberincludes a web and a radially inward extension together defining aninner radial recess, and a radially outward flange separated from theback portion of the body by the web. Additional embodiments aredisclosed herein.

Another exemplary inventive concept that is presented herein provides afitting including first and second threaded fitting components and firstand second conduit gripping devices. When the fitting is pulled-up on aconduit the first fitting component and the second fitting component canbe joined together to a first relative axial position of the firstfitting component and the second fitting component to effect conduitgrip and seal at a first relative axial position, with a rear surface ofthe first conduit gripping device engaging a front surface of the secondconduit gripping device. At least one of the first conduit grippingdevice and the second conduit gripping device comprises a strokeresisting member axially engaging a bearing surface of the other of thefirst conduit gripping device and the second conduit gripping device ata location spaced apart from the rear surface first conduit grippingdevice and the front surface of the second conduit gripping device whenthe first and second fitting components are joined together to the firstrelative axial position, such that a tightening torque beyond the firstrelative axial position is increased by the axial engagement. The strokeresisting member is plastically axially compressed when the first andsecond fitting components are joined together to a second relative axialposition advanced beyond the first relative axial position. Additionalembodiments are disclosed herein.

Another exemplary inventive concept that is presented herein provides aferrule set including a first ferrule having a stroke resisting memberextending axially rearward from a back portion of the first ferrule, anda second ferrule having a radially extending outer flange portion. Amajority of the outer flange portion is radially aligned with a majorityof a rearmost end surface of the stroke resisting member when the firstand second ferrules are aligned about a common central axis. Additionalembodiments are disclosed herein.

Another exemplary inventive concept that is presented herein provides afitting including a first fitting component and a second fittingcomponent that can be joined to said first fitting component to form afitting assembly, and a ferrule receivable between the first fittingcomponent and the second fitting component. The ferrule includes aforward portion that engages a tapered camming surface of the firstfitting component, and a contoured surface extending rearward from theforward portion at a continuous rearward declining angle with respect tothe forward portion. Additional embodiments are disclosed herein.

Another exemplary inventive concept that is presented herein provides aferrule including a forward frustoconical portion, a contoured surfaceextending rearward from the forward portion at a continuous rearwarddeclining angle with respect to the forward portion, and a rear flangeportion extending radially outward of the contoured surface. Additionalembodiments are disclosed herein.

These and other embodiments of various inventions disclosed herein willbe understood by those skilled in the art in view of the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an embodiment of a conduit fitting illustrating one embodimentof one or more of the inventions herein, shown in longitudinalcross-section and in a finger tight position;

FIG. 2 is an enlarged illustration of the portion of FIG. 1 in circle A;

FIG. 3 is an enlarged illustration of the portion of FIG. 1 in circle Abut with the fitting in a complete pulled-up position;

FIG. 3A is a chart illustrating an example of torque versus turns;

FIGS. 4-6A illustrate in perspective, exploded perspective and inlongitudinal cross-section respectively an embodiment of a conduitfitting with torque collar that includes a stroke resisting member;

FIG. 7 illustrates the conduit fitting of FIGS. 4-6A in a finger-tightposition;

FIG. 8 illustrates the conduit fitting of FIGS. 4-6A at a pulled-upposition;

FIG. 9 illustrates the conduit fitting of FIGS. 18-20 in a pulled-upposition past the position of FIG. 8;

FIG. 10 illustrates the conduit fitting of FIGS. 4-6A in a FTP followingthe pull-up of FIG. 9;

FIG. 11 illustrates the conduit fitting of FIGS. 4-6A after a firstremake;

FIG. 12 illustrates the conduit fitting of FIGS. 4-6A in a FTP followingthe pull-up of FIG. 11;

FIG. 13 illustrates the conduit fitting of FIGS. 4-6A after a secondremake;

FIG. 14 illustrates another embodiment of a conduit fitting inlongitudinal cross-section that utilizes a non-integral stroke resistingmember, the fitting being shown in FTP;

FIG. 15 illustrates the conduit fitting of FIG. 14 in a pulled-upposition;

FIG. 16 illustrates the conduit fitting of FIG. 14 in a pulled-upposition past the position of FIG. 15;

FIG. 17 illustrates the conduit fitting of FIG. 14 in a FTP followingthe pull-up of FIG. 16;

FIG. 18 illustrates the conduit fitting of FIG. 14 after a remake;

FIG. 19 illustrates the conduit fitting of FIG. 14 in a FTP followingthe remake of FIG. 18;

FIGS. 20-22 illustrate a cartridging structure and process forcartridging a torque collar to a fitting component;

FIGS. 23 and 24 illustrate alternative embodiments of the embodiment ofFIGS. 4-13;

FIGS. 25 and 26 illustrate alternative embodiments of the embodiment ofFIGS. 14-22;

FIGS. 27-35B illustrate alternative embodiments of a stroke resistingmember;

FIG. 36 is another embodiment of a pull-up by torque fitting in afinger-tight position;

FIG. 37 illustrates the fitting of FIG. 36 after a remake;

FIG. 38 is a chart illustrating an example of torque versus relativestroke;

FIG. 39 is another embodiment of a front ferrule;

FIGS. 40 and 41 illustrate a conduit fitting having a ferrule cartridgeusing a front ferrule of the type illustrated in FIG. 39;

FIG. 42 illustrates an embodiment of a ferrule cartridge with a tool forcartridge assembly, shown prior to cartridging;

FIG. 42A is an enlarged view of a front ferrule as presented in theembodiment of FIG. 42, shown in half longitudinal cross-section andprior to cartridging;

FIG. 42B is another embodiment of a front ferrule, shown in halflongitudinal cross-section and prior to cartridging;

FIG. 42C illustrates geometric relationships for a member that may bepart of a retaining structure for a ferrule cartridge;

FIG. 43 illustrates the ferrule cartridge of FIG. 42 and cartridgingprocess during cartridging;

FIG. 44 illustrates the ferrule cartridge of FIG. 42 after cartridging;

FIG. 45 is an enlarged view of the front ferrule of FIG. 42 aftercartridging;

FIGS. 46-49 illustrate a conduit fitting with a ferrule cartridge in afinger-tight position, after pull-up to 1¼ turns past finger-tightposition and 1⅞ turns past finger-tight pulled-up position;

FIG. 49A is another embodiment of a front ferrule, shown in halflongitudinal cross-section and prior to cartridging;

FIG. 50 is an alternative embodiment of a front ferrule;

FIGS. 51-53 show a cartridging process comparable to FIGS. 43-45 for aferrule cartridge that includes the front ferrule of FIG. 50;

FIGS. 54-56 illustrate a conduit fitting with a ferrule cartridge as inFIGS. 51-53 in a finger-tight position and after pull-up to 1¼ turnspast finger-tight position;

FIG. 56A illustrates the conduit fitting of FIGS. 51-53 after 1.875turns past finger-tight position;

FIG. 57 illustrates another embodiment of a front ferrule;

FIG. 58 illustrates another embodiment of a front ferrule;

FIG. 59 illustrates another embodiment of a front ferrule;

FIG. 60 illustrates another embodiment of a front ferrule; and

FIG. 61 illustrates another embodiment of a front ferrule.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Although the exemplary embodiments herein are presented in the contextof a stainless steel tube fitting, the inventions herein are not limitedto such applications, and will find use with many different metalconduits such as tube and pipe as well as different materials other than316 stainless steel, and may also be used for liquid or gas fluids.Although the inventions herein are illustrated with respect to exemplarydesign of the conduit gripping devices and fitting components, theinventions are not limited to use with such designs, and will findapplication in many different fitting designs that use one or moreconduit gripping devices. In some fittings, in addition to the conduitgripping devices there may be one or more additional parts, for exampleseals. The inventions may be used with tube or pipe, so we use the term“conduit” to include tube or pipe or both. We generally use the terms“fitting assembly,” “conduit fitting” and “fitting” interchangeably as ashorthand reference to an assembly of typically first and second fittingcomponents along with one or more conduit gripping devices. The conceptof a “fitting assembly” thus may include assembly of the parts onto aconduit, either in a finger-tight, partial or complete pull-up position;but the term “fitting assembly” is also intended to include an assemblyof parts together without a conduit, for example for shipping orhandling, as well as the constituent parts themselves even if notassembled together. Fittings typically include two fitting componentsthat are joined together, and one or more gripping devices, however, theinventions herein may be used with fittings that include additionalpieces and parts. For example, a union fitting may include a body andtwo nuts.

The term “complete pull-up” as used herein refers to joining the fittingcomponents together so as to cause the one or more conduit grippingdevices to deform, usually but not necessarily plastically deform, tocreate a fluid tight seal and grip of a fitting assembly on a conduit.The conduit in many cases may also be plastically deformed duringpull-up. A partial pull-up as used herein refers to a partial butsufficient tightening of the male and female fitting components togetherso as to cause the conduit gripping device or devices to deform so as tobe radially compressed against and thus attached to the conduit, but notnecessarily having created a fluid tight connection or the requiredconduit grip that is achieved after a complete pull-up. The term“partial pull-up” thus may also be understood to include what is oftenreferred to in the art as pre-swaging wherein a swaging tool is used todeform the ferrules onto the conduit sufficiently so that the ferrulesand the nut are retained on the conduit prior to being mated with thesecond fitting component to form a fitting assembly. A finger tightposition or condition refers to the fitting components and conduitgripping devices being loosely assembled onto the conduit to an abuttingposition where the conduit gripping devices are in axial contact withand between the male and female fitting components, but without anysignificant tightening of the male and female fitting componentstogether, usually typified by the conduit gripping device or devices notundergoing plastic deformation. We also refer to an initial or firstpull-up or make-up to refer to the first time that a fitting istightened to a complete pulled-up position, meaning that the ferrulesand conduit had not been previously deformed. A subsequent pull-up orremake refers to any complete pull-up after a previous pull-up, whetherthat previous pull-up was the initial pull-up or a later pull-up orremake of the fitting.

We also use the term “fitting remake” and derivative terms herein torefer to a fitting assembly that has been at least once tightened orcompletely pulled-up, loosened, and then re-tightened to anothercompletely pulled-up position. Effective remakes may be done with thesame fitting assembly parts (e.g. nut, body, ferrules), for example, ormay involve the replacement of one of more of the parts of the fittingassembly. An effective pull-up or remake or an effectively pulled-up orremade fitting as used herein is one that is effectively tightened (orre-tightened) to establish a mechanically attached connection with aconduit using the same or in some cases one or more replaced fittingparts, without adverse effects on fitting performance as to fluid tightseal and grip. In other words, an effective remake as used herein meansa remake in which the fitting performance is not compromised or alteredfrom its original performance criteria, specification or rating (forexample, will achieve the same pressure rating upon remake within theallowed number of remakes as may be specified by the manufacturer). Whenwe use the term remake in the context of the various embodiments andinventions herein, we are referring to effective remakes. We use theterms “effective remake” and “reliable remake” interchangeably herein.Reference herein to “outboard” and “inboard” are for convenience andsimply refer to whether a direction is axially towards the center of afitting (inboard) or away from the center (outboard).

We also use the term “flexible” herein to mean a structuralcharacteristic of a member so that the member can deform, strain, bend,deflect, elongate or otherwise move or shift under load withoutfracturing or breaking. This flexible deformation may accompany a straininduced hardening. This flexible deformation may also accompany apermanent set or plastic deformation or may be a plastic deformationwith an attendant elastic deformation, but at least some degree ofplastic deformation is preferred to facilitate remakes. Further, therelative elastic and plastic deformations may be influenced orcontrolled by one or more of a strain hardening of the material fromwhich the member is subsequently fabricated, a heat treatedmetallurgical or precipitation hardening of the material, and a lowtemperature interstitial case hardening of the member after fabrication.

When two threaded parts are tightened together to pull-up a fitting,turns and torque are related factors and applicable to the tighteningprocess. For a tube or pipe fitting, this follows from the fact thatwhen the threaded fitting components such as a nut and body aretightened together, the ferrule or ferrules undergo a plasticdeformation and also in most cases plastically deform the conduit, andin many designs also can involve cutting into the exterior surface ofthe conduit or swaging the exterior surface of the conduit. Thesedeformations, along with engaging threads and other metal to metalcontact within the fitting, necessarily result in an increasing torqueas the nut and body are tightened. But, in many prior known fittingdesigns, there is not necessarily a repeatable and reliable associationbetween pull-up torque and the number of turns it takes past fingertight position to reach the completed pull-up position. Even for highquality high performance fittings such as available from SwagelokCompany, pulling up by torque or feel requires experienced assemblersand the fittings are only recommended to be pulled-up by turns. This isin part due to the fact that for such high quality fittings one of thedesign goals is to reduce pull-up torque and to prevent galling andother torque related issues, thereby further reducing the noticeableeffects of torque at the complete pull-up position even to a highlyexperienced assembler.

For purposes of this disclosure, however, in the context of pulling upor making up a fitting by tightening together two threaded fittingcomponents (for example, a nut and a body), pull-up “by torque” meanstightening the parts together using a prescribed or predetermined orminimum torque without requiring a count of the number of relative turnsand partial turns. The torque may be a distinct or precise torque valueor the prescribed or predetermined or minimum torque may be a range oftorque values. The predetermined torque may be any range of torquevalues, depending on the application. In one exemplary embodiment, thepredetermined torque is any torque at or above a predetermined torquethat either ensures that the fitting is properly pulled-up to grip andseal the conduit, or that effects relative axial displacement of thefitting components that corresponds to the desired number of turns andpartial turns past the reference position, or both. In anotherembodiment, the predetermined torque may be a predetermined torque +/−an acceptable tolerance. For example, the prescribed or predeterminedtorque may be a torque value +/−0 to 15% of a torque value, such as+/−10% of the torque value or +/−15% of the torque value or any rangewithin +/−15% of the torque value. A pull-up “by turns” means tighteningthe parts together using a prescribed or desired number of relativeturns and/or partial turns past a reference position without requiring apredetermined torque. Pull-up by torque and pull-up by turns are used inassociation with both initial pull-up and remakes as further explainedbelow.

We therefore provide, in an exemplary aspect of the present application,a flexible member, for example a stroke resisting member or load bearingmember, having a surface that engages another surface of the fittingassembly during relative axial displacement of the threaded fittingcomponents during pull-up. These engaging surfaces preferably do notengage at the reference position but initially engage after additionalrelative axial displacement past the reference position. This ispreferably the case for the first pull-up that a fitting undergoes.These engaging surfaces initially engage each other preferably to eithercoincide with or closely correspond to the relative axial displacementof the threaded fitting components that may be associated with thenumber of turns and partial turns past finger tight position forcomplete pull-up had the fitting been pulled-up alternatively by turns.In this way, a fitting can be optionally pulled-up by turns, by torqueor both. Depending on the applications and criticality of the pull-upprocess, we do not require that in all situations that the surfacesengage precisely at the point of the prescribed relative axialdisplacement past the reference position. However, for repeatable andreliable pull-ups, it is preferred that the surfaces engage in closealignment with the corresponding relative axial displacement used forpull-up by turns. In other words, it is preferred but not required inall cases that the surfaces engage or make contact with each other upontightening of the fitting components to a relative axial displacementthat closely aligns with the prescribed number of turns and partialturns past the reference position. In this manner also, the amount ofstroke used during any pull-up may be controlled so as to maximize oroptimize the number of useful remakes of the fitting.

In the exemplary embodiments, when the surface of the flexible memberengages the other surface of the fitting assembly, the manual assemblerpreferably will sense a distinct increase in the torque required tocontinue tightening the fitting components together. But alternatively,when using a torque applying tool, such as a torque wrench, the tool maybe used to effect the same pull-up although the assembler will notnecessarily sense the torque increase.

The words “limiting” and “resisting” as used in connection with strokeherein are not intended to include the idea of a positive stop. Ratherwe use the terms stroke limiting and stroke resisting interchangeably tomean that the flexible member or torque collar resists relative axialdisplacement upon contact with the engaging surface, but does notprevent further axial advance. This is important because positive stopsdo not facilitate effective and reliable remakes. For example, stopcollars typically are removed when a fitting is remade in order to allowreliable additional axial advance for remake.

Because we can optionally use the flexible member for multiple remakes,it is notable that for the very first pull-up of a fitting, meaning noother prior pull-up that deformed the conduit gripping device(s), thereference position is the initial finger tight position past which thereis needed a number of full and/or partial turns (i.e. relative axialadvance) to further advance the fitting components together to effectpull-up. But when comparing the very first pull-up with subsequentremakes, there is not the same degree of additional relative axialdisplacement or stroke needed to assure grip and seal. In other words,each remake typically involves only a smaller additional partial turnpast the reference position. The reference position for a remake is theposition that the components were at after the last pull-up. This priorpull-up position (the remake reference position) tends to be at aposition where the components, especially the conduit gripping devices,have already taken a set but also may have experienced a bit of elasticspring back or relaxation. In the context of the flexible member usedfor pull-up by torque, for each remake the engaging surfaces mayactually be very close or even touch at the remake reference position,but the flexible member will still allow further axial advance to effectthe remake of the fitting. Therefore, the idea of the engaging surfacesnot contacting initially until additional relative axial displacement ofthe threaded fitting components, may only in practice apply to the veryfirst pull-up that the fitting is subjected to, and not necessarily,although it may, for each remake. Particularly after a number ofremakes, the conduit gripping devices become more and more set and fixedin position on the conduit so that later remakes involve possiblyimperceptible further relative axial advance of the fitting componentsto effect conduit grip and seal.

Moreover, while the exemplary embodiments herein illustrate the flexiblemember surface and the engaged surface as engaging at the very firstpull-up, such is not required in all cases. For example, the flexiblemember may be designed so that a desired torque can be used to effectthe initial pull-up, but that the surfaces do not engage until the firstor subsequent pull-up.

As will be further described hereinbelow, the flexible member may alsoprovide the capability for an intrinsic gauging function associated withthe fitting assembly. By intrinsic we mean that the fitting assemblyself-contains or inherently or integrally includes the gauging functionwithout necessarily the need for an external tool, although the use ofan external tool may also be facilitated for different embodiments.Because the flexible member presents a repeatable and reliablerelationship between pull-up by torque and relative axial displacement(relative turns past the reference position), the gauging feature may beused for not only gauging initial pull-up by torque but also initialpull-up by turns. Moreover, the flexible member facilitates a gaugingfunction and structure, intrinsic or otherwise, that can be used forgauging remakes by torque or turns.

While various inventive aspects, concepts and features of the inventionsmay be described and illustrated herein as embodied in combination inthe exemplary embodiments, these various aspects, concepts and featuresmay be used in many alternative embodiments, either individually or invarious combinations and sub-combinations thereof. Unless expresslyexcluded herein all such combinations and sub-combinations are intendedto be within the scope of the present inventions. Still further, whilevarious alternative embodiments as to the various aspects, concepts andfeatures of the inventions—such as alternative materials, structures,configurations, methods, circuits, devices and components, alternativesas to form, fit and function, and so on—may be described herein, suchdescriptions are not intended to be a complete or exhaustive list ofavailable alternative embodiments, whether presently known or laterdeveloped. Those skilled in the art may readily adopt one or more of theinventive aspects, concepts or features into additional embodiments anduses within the scope of the present inventions even if such embodimentsare not expressly disclosed herein. Additionally, even though somefeatures, concepts or aspects of the inventions may be described hereinas being a preferred arrangement or method, such description is notintended to suggest that such feature is required or necessary unlessexpressly so stated. Still further, exemplary or representative valuesand ranges may be included to assist in understanding the presentdisclosure, however, such values and ranges are not to be construed in alimiting sense and are intended to be critical values or ranges only ifso expressly stated. Moreover, while various aspects, features andconcepts may be expressly identified herein as being inventive orforming part of an invention, such identification is not intended to beexclusive, but rather there may be inventive aspects, concepts andfeatures that are fully described herein without being expresslyidentified as such or as part of a specific invention, the inventionsinstead being set forth in the appended claims. Descriptions ofexemplary methods or processes are not limited to inclusion of all stepsas being required in all cases, nor is the order that the steps arepresented to be construed as required or necessary unless expressly sostated.

We note at the outset that as described in detail hereinabove, theability to successfully remake a conduit fitting by torque or turns,particularly for a number of remakes, requires the ability to provideincremental relative axial stroke or advance of the nut and body. Thisincremental relative axial stroke decreases or decrements with eachadditional remake and with sufficient remakes can become almostimperceptible. This can be attributed to the ferrules in particularbeing more and more fixed in position and alignment so that as thenumber of remakes increases it takes less stroke to return the ferrulesto a proper position for conduit grip and seal. The additional relativeaxial stroke with each remake can be provided by plastic deformation ofa number of different components and structural features of the fitting,either alone or in various combinations, however, one of the advantagesof using a stroke limiting or stroke resisting arrangement, such as atorque collar—whether integral or as a separate part—is that theadditional relative axial stroke can be better controlled by using thetorque collar to provide a controlled stroke resisting feature at apredetermined torque that corresponds to the predetermined axialdisplacement needed to effect proper conduit grip and seal. Statedanother way, the stroke resisting arrangement provides a surface thatinitially engages another surface of the fitting assembly at a point ofrelative axial displacement of the threaded fitting components past thereference position (particularly but not necessarily only for the veryfirst pull-up of a fitting) and that preferably aligns with or isclosely associated with the desired relative axial displacementcorresponding to a pull-up by turns. For example, the engaging surfacesmay first contact each other at a relative axial displacement past thefinger tight position of the threaded fitting components that alignswith about one and a quarter turns past finger tight position (for afitting that can alternatively be pulled-up by turns by counting one andone quarter turns past finger tight position). The stroke resistingarrangement also presents a controllable plastic deformation andadditional relative axial stroke or displacement between the nut andbody for each remake, rather than having to rely on plastic deformationof a myriad of other possibilities.

Therefore we consider that the inventions herein may be realized in manyforms, including but not limited to the use of a separate or integraltorque collar to provide pull-up by torque, but if so desiredalternatively pull-up by turns, or both, the geometry of a fittingcomponent having a torque collar included therewith, integral ornon-integral, and the use of a fitting component geometry that providesa gauging feature for a fitting that can be pulled-up by torque and alsofor a fitting that can be pulled-up by turns, with gauging for remakesas well as the first pull-up.

Several, but not all, embodiments of the inventions disclosed hereinrelate to providing a fitting for conduits that may be pulled-up bytorque or optionally by turns. There are a number of different aspectsto this concept. The exemplary embodiments herein disclose apparatus andmethods for a fitting that may be pulled-up by turns, by torque or both.Advantageously, although not required, the fittings may be initiallypulled-up by torque or turns and undergo numerous remakes by torque orby turns. Still further, these remakes may each be accomplished with thesame torque value or range of predetermined torque values as the initialmake up or prior remakes. As still another important aspect, apparatusand methods are provided by which a fitting that is designed to bepulled-up by turns may be adapted as taught herein to alternatively bepulled-up by torque.

As described herein, a fitting designer may select a predeterminedtorque that will achieve a leak-tight initial pull-up within whateverconfidence level the manufacturer desires. Some manufacturers may wantthe predetermined torque to give a leak-free initial pull-up every time,others may want ninety-seven percent reliability, others maybe evenless, to give some examples. Even if the predetermined torque does notproduce 100% leak-free initial pull-up, the assembler can still furthersnug up the fitting a bit more if needed, while still allowing for alarge number of remakes by torque. The predetermined torque may beselected to produce a reliable initial pull-up for any tolerancestack-up as desired. A stroke resisting feature is provided such thatthe feature is first engaged either at the initial pull-up or after oneor more remakes, so as to limit the stroke used during remakes. Thisarrangement may facilitate many remakes even to the same predeterminedtorque value if so desired, even as many as fifty or more reliableremakes. The initial pull-up by torque may be selected so as to use thestroke needed to effect proper grip and seal, and optionally up to anoptimized stroke beyond which successful reliable remakes can beachieved with small incremental axial advance, as controlled then by thestroke resisting feature.

For example, for a given one and a quarter turns fitting designpopulation, assume 15 N-m (Newton meters) is a predetermined torque forinitial pull-up a fitting having a high tolerance stack-up. That same 15N-m torque will also pull-up a fitting at the low end of the tolerancestack-up, but would result in more than one and a quarter turns, maybeeven two full turns or more. The torque limiting feature may be axiallypositioned so as to engage before such excessive stroke is consumed, andthus may but need not engage during the initial pull-up. For fittingsnear nominal or on the higher side of the tolerance stack-up, however,the torque limiting feature might not engage until the first, second orpossibly even later remake. The torque limiting feature has thuspermitted pull-up by torque to a predetermined torque for a fittingdesign population, while at the same time preventing over-tightening forlow end tolerance stack-up assemblies, thereby facilitating manyreliable remakes. The stroke resisting feature also provides a strokecontrolled pull-up for each remake by torque, which also contributes toallowing many reliable remakes by torque.

Not all fittings from manufacturers will have similar torque to strokecharacteristics. Some manufacturers may have looser tolerances ondimensions and material properties, while others may have very tightcontrols. Some fittings may be designed with torque reducing featuressuch as the use of lubricants, or some fittings may be designed withsofter materials for lower pressure applications. But regardless of themultitude of choices made for a fitting design, a predetermined torquemay be selected to assure the proper stroke to achieve conduit grip andseal. This predetermined torque may optionally be set high enough thatthe stroke resisting feature will engage on every pull-up including theinitial pull-up and remakes. Once engaged, whether first at the initialpull-up or a later remake, the stroke resisting feature will allowcontrol of the additional axial movement or stroke for each remake, thusmaximizing the available number of remakes for a particular fittingdesign.

Co-pending U.S. Patent Application Publication No. 2010/0213705 (the“'705 Application”), entitled “Conduit Fitting with Torque Collar,” andincorporated herein by reference in its entirety, describes a strokeresisting arrangement utilizing a dynamic wedge concept, summarized anddisclosed more generally below and in FIGS. 1-3.

With reference to FIGS. 1-3, a stroke resisting arrangement 40 may beincluded with a fitting 10 to facilitate pull-up by torque. While manydifferent forms of stroke resisting features may be utilized, in theillustrated embodiment, the stroke resisting arrangement includes aseparate annular ring torque collar having an outward facing wedgesurface 48 and a threaded fitting nut having an inward facing tapersurface 50 that are axially pressed against each other when the nut 14is pulled up on the body 12. Also, while the illustrated example showsthe inward facing taper surface 50 as being axially advanced against theoutward facing wedge surface 48 by tightening of the nut 14, in otherembodiments (not shown), an outward facing wedge surface may be axiallyadvanced against an inward facing taper surface by tightening of afitting nut. Further, as described in several embodiments of the aboveincorporated '705 Application, an integral feature of one or both of thethreaded fitting components (i.e., an “integral torque collar”) maysimilarly provide interengaging wedge and taper surfaces that functionas a stroke resisting arrangement.

As viewed in cross-section, the wedge surface 48 may be formed at anangle α relative to the central axis X (FIG. 1) of the fitting 10, andthe taper surface 50 may be formed at an angle relative to the centrallongitudinal axis of the fitting. In one embodiment, when the fitting 10is in the finger-tight position, the taper surface 50 is axially spacedfrom the wedge surface 48, and after a completed pull-up, the tapersurface 50 is axially pressed against the wedge surface 48. The outwardfacing surface 48 is referred to as a wedge surface because that surfaceacts to significantly resist axial advance of the nut after the tapersurface 50 first makes contact with the wedge surface 48, yet will allowadditional axial stroke during subsequent remakes. This contact producesa distinct and optionally sharp increase in torque that can be eithersensed by the assembler or that will allow a torque wrench to be used tomake up the fitting 10. The angles α and β may be but need not be thesame. Many different angle values may be used, including, for example,about ten degrees to about seventy-five degrees, or about 45 degrees.

Although it is optional to use the same predetermined torque for remakesas used for the initial pull-up, it can be expected that this will be agreat convenience for the end user as only a single torque wrench ortorque specification needs to be used. The stroke resisting arrangement40 facilitates this benefit by providing a controlled additional axialdisplacement with each remake at the prescribed applied torque. Theadditional axial displacement with each remake will depend on manyfactors, including but not limited to the angles of the engagingsurfaces 48, 50, friction values, hardness, yield strength, creep and soon, as well as how many remakes have already been made.

A leading edge 54 of the taper surface 50 will initially contact thewedge surface 48 as the fitting 10 is pulled-up. Further advance of thenut 14 relative to the body 12 will cause the forward portion 56 of thewedge surface 48 to enter the frustoconical recess defined by the tapersurface 50 with tighter and tighter engagement between the wedge surface48 and the taper surface 50. This will result in a distinct andsignificant increase in torque compared to the torque increase thatwould otherwise be noted for the same nut stroke if the stroke resistingarrangement 40 were not present. The wedge surface 48 and the tapersurface 50 cooperate during pull-up to produce a distinctly andperceptible increase in torque that is higher than the predeterminedtorque value that corresponds with the predetermined relative axialstroke for proper make up of the fitting 10 and is accompanied by asignificant resistance to additional relative axial stroke of the nutand body. In other words, the wedge surface 48 and the taper surface 50are designed to produce a distinct torque increase due to the increasingload between the wedge surface 48 and the taper surface 50 when combinedwith the interaction of the conduit gripping devices and the conduit. Asillustrated in FIG. 3, this cooperation between the wedge surface 48 andthe taper surface 50 may result in significant surface to surfacecontact and load between the wedge surface 48 and the taper surface 50,but this drawing is only intended to be exemplary. The actual amount ofcontact for initial pull-up as well as one or more remakes will bedetermined by overall design criteria for the fitting 10.

FIG. 3A is an exemplary chart of torque versus turns of the nut relativeto the body (stroke). Actual values for the stroke and torque are notimportant but rather the concept of the relationship between torque andstroke. Note that for up to a desired or predetermined stroke, thetorque gradually increases as represented by slope A. Then the torquerate of increase changes distinctly after the nut has engaged the torquecollar, such as represented by slope B. In the transition region AB, thetorque collar 40 can be designed to produce a significant resistance(sensed as torque or corresponding to a specified torque such as couldbe used to enable a torque wrench to be used for pull-up) to additionalstroke with a tight correspondence to torque. It is important torecognize that the graph in FIG. 3A is only exemplary and intended toillustrate some of the concepts herein. For example, where thetransition region AB occurs relative to the number of turns can beshifted left and right. Also, the amount of torque change and theresistance to further stroke can also be set by the design of the strokeresisting arrangement.

Another aspect of the stroke resisting feature is to allow remakes ofthe fitting 10. This may be accomplished by designing the strokeresisting arrangement 40 to allow further axial advance of the nut 14relative to the body 12 for fitting remake, beyond the axial position ofthe nut 14 relative to the body 12 for the just prior pull-up. In thisembodiment then, the wedge surface 48 thus allows for remakes byallowing for further axial advance of the nut 14 relative to the body12. However, other surface profiles may be used to provide the desiredtorque increase relative to stroke of the nut while also allowing forone or more remakes. We have found that the angle α of about forty-fivedegrees can result in twenty-five or more remakes. The torque increaseis also a function of the shape of the taper surface 50. The designermay choose those shapes and angles that best achieve the desiredperformance for pull-up by torque and remakes.

Many factors may be used to control the amount of additional axialstroke for each remake. In addition to the angles and profiles of thewedge surface 48 and the taper surface 50, additional axial displacementactually occurs due to either radially outward flaring or expansion ofthe nut 14, radially inward compression of the torque collar 40, plasticdeformation such as creep at the engaging surfaces 48, 50, or anycombination thereof. These deformations may be controlled, for example,through the hardness of the components, surface finish and so on. Thedesigner therefore has available a number of different factors includingothers not listed here, to effect controlled axial displacement witheach remake, without adversely affecting the performance of the fitting.

Many factors will influence the final design, including but not limitedto the hardness of the torque collar 40, surface characteristics of thewedge surface 48 and the nut taper surface 50 to effect desired frictionbetween the torque collar 40 and the nut 14, thread pitch (for the nutand body), the axial distance between the leading edge 54 that initiallycontacts the wedge surface 48 and the drive surface 22 that contactsthat back ferrule 20, and the angles α and β.

Because the torque collar 40 allows for one or more remakes, the wedgesurface 48 may be thought of as a dynamic wedge in that the torquecollar permits controlled additional relative axial advance or stroke ofthe nut and body for each remake, meaning that the contact position ofthe nut taper surface 50 against the wedge surface 48 will change, evenever so slightly, with each remake. The torque collar 40 therefore willpreferably characterized by a high yield strength but may yieldsomewhat, to facilitate many remakes when such is a desired performancecharacteristic of the fitting 10.

In accordance with one of the inventive concepts presented in thisdisclosure, a torque collar or other stroke resisting feature isprovided in the form of a member, for example a load bearing flexiblemember or stroke resisting member of one or both of the fittingcomponents, in which the flexible member may be characterized by a yieldstrength that permits the flexible member to deflect under load in acontrolled manner so as to allow additional relative axial displacementof the nut and body during remakes. The flexible member may beintegrally formed, such as by machining for example, with one or both ofthe fitting components, or integrated therewith, such as by welding forexample, to form an integral structure. The flexible member may beprovided on a nut, a body, a nut and body, and may be used with femaleand male conduit fittings as set for below. The deflection of theflexible member under load provides the desired plastic deformation tofacilitate additional relative axial stroke during one or more remakesof a conduit fitting, whether the initial pull-up or the one or moreremakes is by torque or by turns. It should be noted that although theload bearing flexible member is designed to exhibit a desired plasticdeformation for each pull-up, this does not imply nor necessitate thatthere be no elastic deformation. The load bearing flexible member, forexample, may be designed with a flexure or give so as to allow the loadbearing flexible member to deflect under load. The load bearing flexiblemember may indeed exhibit some elastic deformation, however, in order toaccommodate additional remakes by torque, it will be desired that theload bearing flexible member also undergo some degree of plasticdeformation or take a set under load in response to each remake orpull-up.

With reference to FIGS. 4-6A we provide another embodiment of a conduitfitting 400 (also referred to herein as a fitting for short) with atorque collar 402 that may be used to facilitate pull-up by torque. Asin the other embodiments herein, the torque collar 402 does not precludethe fitting 400 from being pulled-up in a traditional manner by turns.The fitting 400 may comprises all metal parts, for example, stainlesssteel, however other materials may be used as needed as well as fittingsthat do not use all metal parts.

The fitting 400 may include a first fitting component 404 which may bein the form of a threaded body 404 and also will be referred to hereinas the body 404 for short; and a second fitting component 406 which maybe in the form of a threaded nut 406 and also will be referred to hereinas the nut 408 for short. Although the embodiment of FIGS. 4-6Aillustrates a particular configuration of the body 404, in this examplea union, many different types and configurations for the body 404 mayalternatively be used as is well known. The common features of a body404 (identified below) regardless of geometry or configuration used in aconduit fitting include a threaded portion that mates with threads of anut, a frustoconical camming mouth that receives the forward portion ofa conduit gripping device, and a bore that receives an end of a conduit.The conduit gripping device may be realized in many forms as is wellknown, including but not limited to a single ferrule or a pair offerrules, the latter commonly referred to as a front ferrule and a backor rear ferrule. In a two ferrule fitting, a forward portion of thefront ferrule engages the camming mouth of the body, and a forwardportion of the back ferrule engages a frustoconical camming surface at arearward portion of the front ferrule. The camming surface and cammingmouth need not be frustoconical as is well known. Furthermore, althoughthe embodiment of FIGS. 4-6A et seq. illustrate a male stylefitting—meaning that the body 404 is male threaded and the nut 406 isfemale threaded, alternatively the inventions may be used with femalestyle fittings.

The fitting 400 includes a first or front conduit gripping device 408and a second or back conduit gripping device 410. We will also referherein to these conduit gripping devices as ferrules, but structuresother than what may be commonly referred to as ferrules mayalternatively be used for the conduit gripping devices. The conduitgripping devices 409, 410 are axially assembled in a space definedbetween the body 404 and the nut 406. References herein to axial andradial and similar terms are referenced to the longitudinal axis X inthe drawings. In this case the axis X is the central longitudinal axisof the fitting 400 and also is coaxial with the central longitudinalaxis of a conduit (not shown in FIGS. 4-6A but see FIG. 7 et seq.) thatis inserted into the fitting 400. However, the axis X may be anylongitudinal reference axis.

The pull-up process begins with assembling the fitting 400 to a fingertight position which is the position of FIG. 6. The nut 406 and the body404 have a threaded mechanical connection 412 as noted above. The nut406 includes a ferrule drive surface 414 that contacts the back end 416of the back ferrule 410. The back ferrule 410 has a forward portion 418that contacts a frustoconical camming surface 420 at a rearward portionof the front ferrule 408. And, a forward portion 422 of the frontferrule 408 is received in and contacts a frustoconical camming mouth422 of the body 404. The finger tight position is thus one where thenut, the two ferrules and the body are in intimate contact with eachother but there is no actual tightening of the assembly. This fingertight position is historically a reference position for pulling upconduit fittings by turns. For example, a fitting may be designed to bepulled-up 1.25 turns past finger tight position (also herein referred toas FTP for short). But other fitting designs may be pulled-up to adifferent specification, for example, 1.5 turns past FTP. Although notshown in FIG. 6, a conduit T is inserted into the fitting 400 with aforward end of the conduit T contacting an interior shoulder 426 of thebody 404, known in the art as bottoming. But alternative body designsmay not use the shoulder 426. Also, although typically the fitting 400may be assembled first and then the conduit is inserted, it is alsoknown to pre-swage the ferrules 408, 410 onto the conduit end (with thenut 406 retained with the ferrules on the conduit after pre-swage) priorto finger tight assembly with the body 404, such that the referenceposition for pulling up the fitting by turns to a prescribed relativeaxial position may in some embodiment be this partially tightened or“pre-swaged” condition. In either case, the finger tight position is asshown in FIG. 6 (without the conduit being shown). FIG. 6, for example,illustrates a common arrangement of the parts for shipping or storage.

The number of turns (full and partial) past the FTP (also referred toherein as relative rotation between the body 404 and the nut 406)directly corresponds to relative axial stroke or translation between thebody 404 and the nut 406 as the fitting 400 is pulled-up (also referredto herein as tightening the fitting). As noted, fittings are usuallyspecified by the manufacturer to be pulled-up a specific number of turnsand partial turns past the reference position, for example, the FTP.Such is the case for the first or initial time that a fitting ispulled-up. For remakes, typically the fitting is again assembled to theFTP and then tightened or snugged up for a partial turn, for example,approximately 0.125 turns although this amount will depend in part onhow many remakes are made because the additional stroke consumed duringremakes becomes smaller as the number of remakes increases.

The amount of relative axial stroke that corresponds to the number ofturns and partial turns past the FTP depends on the design of thefitting, the thread pitch of the threaded mechanical connection 412 andthe fitting size. Fitting sizes are commonly expressed in terms of thenominal outer diameter of the conduit with which the fitting will beused. For example, a quarter inch fitting is used for quarter inchtubing. Metric equivalents are also known. The exemplary embodimentsherein illustrate a ¼ inch (or 6 mm metric) fitting, but the inventionsherein may be used on any size fitting.

The manufacturer specifies the number of turns and partial turns pastthe reference position (the FTP typically) because the correspondingrelative axial stroke between the nut 406 and the body 404 acts to drivethe ferrules together and cause the ferrules to deform such that theferrules grip and seal the conduit so as to form a fluid tightmechanical connection. As an example, for a fitting that is specified tobe pulled-up the first time to 1.25 turns past FTP, it means that 1.25turns are needed to assure the needed axial stroke of the ferrules, nutand body so that the ferrules 408, 410 grip and seal the conduit T.Again, remakes do not involve the same number of turns as the initialpull-up because the ferrules have already been plastically deformed togrip and seal the conduit. For remakes, it is only necessary to returnto a FTP and then snug up the fitting, for example, with a partial turnof 0.125 or as otherwise specified by the manufacturer. It should benoted, as in well known, that the FTP reference position for remakes isa function of the just prior pull-up due to the plastic deformation ofthe ferrules. But for both remakes and an initial pull-up, the FTPreference position is that position at which the nut 406 contacts theback ferrule 410 with the ferrules in contact with each other and thefront ferrule 408 in contact with the camming mouth 424 of the body 404.

The fitting 400 conveniently may be pulled-up by torque or by turns.Pulling up a fitting by turns is the traditional way to pull-up aconduit fitting onto a conduit so that the conduit gripping device ordevices grip and seal the conduit. But as noted in the embodimentshereinabove, our inventions allow a fitting alternatively to bepulled-up by torque rather than having to count turns. The torque collar402 provides this capability. Remakes may also be by torque or by turns.

The torque collar 402 may be integral with the nut 406 to form aone-piece component. Alternatively, the torque collar 402 may be aseparate part, or may be a separate part that is attached to orcartridged with the nut 406 as described hereinbelow. Whether the torquecollar 402 is integral with the nut 406 or a separate part, the torquecollar deforms in a similar manner and may be used to effect pull-up ofthe fitting 400 by torque rather than by turns. As still a furtheralternative embodiment, the torque collar may be integral with the body404 to form a one-piece component.

The torque collar 402 is generally in the form of an annular strokeresisting—also alternatively referred to herein as strokelimiting—member 428 (also referred to herein as a member 428). Thestroke resisting member 428 provides a structure that may be used toresist additional relative stroke between the body 404 and the nut 406during pull-up. In the integral version of FIGS. 4-6A, once the distalend surface 430 of the stroke resisting member 428 contacts a contactingsurface 432 of the body 404, further relative rotation between the body404 and the nut 406 applies an axial load or compression on the member428. Preferably, the axial position and the inside diameter of themember 428 is sufficient to provide an axial and radial gap from thethreaded connection 412. The member 428 may be designed as needed toabsorb this load to resist additional relative axial stroke between thebody 404 and the nut 406. This resistance may be used to cause asignificant or sharp increase in torque required to continue tighteningthe body 404 and the nut 406 together, similar in effect to the othertorque collar embodiments described herein that use engaging surfaces.Therefore, the torque collar 402 may be used to allow pull-up by torquerather than pull-up by turns. The torque collar 402 may be designed toexhibit the desired increase in torque at a desired relative axialdisplacement of the body 404 and the nut 406 (i.e., a prescribedrelative axial position of the body and nut) that corresponds withsufficient relative axial stroke to cause the ferrules 408, 410 to gripand seal the conduit T. As an example, the increase in torque may bedesigned to occur at a first relative axial position of 1.25 turns pastthe FTP. As described hereinabove, the torque collar 402 allows asignificantly tighter control between relative stroke and pull-up torquethan can be achieved without use of a torque collar.

In addition to resisting additional axial stroke, the member 428 isdesigned to plastically deform in a controlled manner so as to take aplastic set. As described in detail above, pull-up by torque uses astructure that takes at least a partial plastic set during pull-up sothat pull-up by torque may also be used on remakes. As described aboveand in the above incorporated '705 Application, the torque collar may bedesigned so that the same torque may be used for remakes as is used forthe initial pull-up. Alternatively, a different torque may be used forremakes if so needed.

In an embodiment, as illustrated in FIG. 6, the member 428 may bedesigned to deform in a controlled manner when placed under axial loador axial compression, such that the member is axially compressed to areduced axial length, relative to an initial axial length of the member.The deformation may be but need not be in the form of buckling or mayinclude buckling as an optional form of deformation. Now, the load onthe member 428 alternatively need not be primarily axial, and in anycase the resultant deformation may involve radial and axial forces, andin some designs and application these radial and axial forces mayproduce radial expansion and other deformations as will be apparent fromthe descriptions below. The buckling or other plastic deformation asneeded will allow the assembler to remake the fitting 400 byreassembling the parts to a FTP and re-tightening the body 404 and thenut 406 together until the member 428, with a reduced axial length dueto plastic axial deformation, again contacts the surface 430 of the bodyand the resultant torque increase occurs.

The member 428 includes a first cylinder portion or first axiallyextending wall portion 434 and a second cylinder portion or secondaxially extending wall portion 436. A web 438 connects the firstcylinder portion 434 with the second cylinder portion 436. The web 438may be designed with a geometry that facilitates a deformation, forexample, a buckling action. Other deformations may be used besidesbuckling. The first wall portion 434 may have a first inner diameter D1and the second wall portion 436 may have a second inner diameter D2.Preferably, although not necessarily, the diameter D1 is less than thediameter D2. Alternatively, the diameters D1 and D2 may be the same orD2 may be the smaller diameter compared with D1. The outer diameters ofthe first and second wall portions may likewise vary with respect toeach other. The member 428 has a first or proximal end or proximal ringportion 428 a that is connected to an axially inward end 406 a of thesecond fitting component 406 (the surface 406 a may be radial or mayalternatively include a draft or taper.) The first wall portion 434 mayextend from an inner radial portion of the proximal ring portion, andmay blend to the main body 440 of the nut 406 with an optional taperedportion 442. An enlarged flange or distal ring portion 444 may bedisposed at a second or distal end 428 b of the member 428, which isaxially opposite the proximal end 428 a, with the second wall portion436 extending axially from an inner radial portion of the distal ringportion 444. The web 438 is angled with respect to each of the first andsecond wall portions to define a hinge portion, and may be joined withthe first cylinder portion 434 by a radius 438 a and with the secondcylinder portion 436 by a radius 438 b. These radii may be thought of ascreases or hinges that facilitate controllable deformation, for examplebuckling, of the web 438 when the member 428 is under axial load oraxial compression. The first and second wall portions and the web may beprovided with radial thicknesses that are smaller than correspondingradial thickness of the proximal and distal ring portions, for example,to facilitate buckling or other such controllable deformation. In oneembodiment (not shown), the distal ring portion may have a radialthickness that is substantially the same as the second wall portion. Instill other exemplary embodiments, the first and second axiallyextending wall portions may extend at an angle with respect to a centralaxis, such that the inner and outer diameters of the first and secondwall portions vary, for example, to facilitate buckling or other suchcontrollable deformation in response to an axial load.

The geometry of the member 428 may alternatively be different from theembodiment of FIG. 6. But the use of the tapered portion 442, the web438, the two cylinder portions 434 and 436 and the enlarged flange 444,as well as material properties and wall thicknesses, allow the designermany options for controlling the deformation, for example by buckling ofthe web 438, to control pull-up torque versus relative axial strokebetween the body 404 and the nut 406. In particular, the geometry andcharacteristics of the member 428 may be different among different sizefittings. Having the deformable torque collar integral with the nut 406rather than the body 404 allows much simpler and cost effectiveimplementation of the torque collar concept. This is because the body404 as noted above may have many different configurations, yet the nuts406 that mate with the body all basically are the same other than as tosize.

Note that in contrast to the dynamic wedge embodiments of the '705Application described hereinabove, torque is controlled by axialcompression of the torque collar 402 rather than engaging surfaces suchas one or more engaging tapered surfaces. The member 428 distal endsurface 430 may simply be a radial surface as illustrated, although suchis not required, and the contacting surface 432 of the body 404 may alsobe a radial surface as illustrated, although again such is not required.For example, the contacting surface 432 of the body 404 may include asmall draft or outward taper, for example about 2°. The distal endsurface 430 may also include an optional taper or draft. The draftangles may be selected as needed.

FIGS. 7-13 illustrate an embodiment of a deformation of a strokeresisting member 428, for example, by a buckling action. These figuresare representations of FEA analysis of the fitting 400 during variousstages of pull-up and remake. FIG. 7 shows a finger tight position asdescribed above prior to an initial or first-time pull-up of the fitting400. Note the axial end to end contact of the nut 406, the back ferrule410, the front ferrule 408 and the body 404, but there is no deformationor stress applied to the parts in the FTP as is well known. The exampleshown in FIGS. 7-13 is for a ¼ inch conduit fitting but the descriptionwill apply for any size fitting including metric sizes. For initialpull-up as well as remakes, there will be a gap G between the distal end430 of the member 428 and the body contacting surface 432. In the FTPfor the various drawings we use G1, G2 and so on to distinguish the gapG that is presented during different pull-ups and remakes of a fitting;but we also generally designate the gap G in the drawings as well forreference purposes. Therefore, the different designations of G1, G2 andso on are examples of the gap G at the FTP. Accordingly, for an initialpull-up there is an axial gap G1 between the distal end surface 430 ofthe member 428 and the oppositely facing contacting surface 432 of thebody 404. In an embodiment, the axial gap G1 may correspond with therelative axial stroke needed between the body 404 and the nut 406 toeffect an initial pull-up of the fitting 400 so that the ferrules 408,410 grip and seal the conduit T. This may be used, for example, when aspecified torque may be used that empirically will be known to achievethe desired relative axial stroke for initial pull-up, whether contactis made or not between the member 428 and the body 404 during theinitial pull-up. Alternatively, the member 428 need not make contactwith the body 404 on the initial pull-up of the fitting 400, but maymake contact only after one or more remakes of the fitting 400 if sodesired. Designing at what relative axial stroke to have the member 428first make contact with the body 404 is a design choice based in part onhow much control of the stroke is desired to optimize the number ofremakes of the fitting 400. But, such contact is useful after one ormore remakes because the torque collar 402 provides control of thestroke versus torque relationship so as to reduce over-torque which canwaste stroke that could otherwise be used for additional remakes.

FIG. 8 illustrates the fitting 400 just prior to an initial pulled-upposition, for example a relative axial displacement between the body 404and the nut 406 that corresponds with just short of 1.25 relative turnsof rotation between the body 404 and the nut 406. Note that in thisexample, the member 428 distal end surface 430 is in contact with thebody contacting surface 432, thus reducing the prior FTP gap G1 to zero.In other words, the full stroke represented by G1 has been consumed onthe initial pull-up, just as if the fitting had been pulled-up by turnsrather than by torque. But because the contact between the member 428and the body 404 will cause a significant and controlled increase inpull-up torque, the fitting 400 can be pulled-up by torque rather thanby counting turns and partial turns (although alternatively the fittingmay also be pulled-up by turns as noted hereinabove). Also note that theferrules 408, 410 are deformed so as to grip and seal the conduit T.This is evidenced by the back ferrule forward portion 418 biting intothe outer surface of the conduit, which provides conduit grip, and thefront ferrule forward portion 422 being wedged between the camming mouth424 of the body and the outer surface of the conduit T so as to formfluid tight seals against the camming mouth surface 424 and the outersurface of the conduit T. Other fitting designs may have differentdeformations of the ferrules and different ways to provide conduit gripand seal. But for any fitting, there will be a relative axial strokebetween the body 404 and the nut 406 that effects conduit grip and sealby the conduit gripping device or devices.

FIG. 8 could also be representative of the fitting 400 at the initialpulled-up position of relative axial displacement that corresponds with1.25 turns. This could be the case, for example, where contact is eithernot made or is lightly made between the member 428 and the body 404 atthe initial pulled-up position. In such an example, there would not beany appreciable deformation of the member 428.

FIG. 9 shows the fitting 400 in the initial pulled-up position. Once themember 428 makes contact with the body 404 (as in FIG. 8), furtherrelative axial displacement (i.e. tightening) of the body 404 and thenut 406 places the member 428 under axial load or axial compression.This axial load or axial compression stresses the web 438. The web 438deforms, such as for example by a buckling action, at the creases 438 aand 438 b. Note that the second cylinder portion 436 may flare outwardlywhile the first cylinder portion 434 may compress inwardly.Alternatively, the first cylinder portion 434 may flare outwardly andthe second cylinder portion 436 may flare inwardly; or both cylindricalportions 434, 436 may flare in the same direction, inwardly oroutwardly. Preferably, any inward flaring will be controlled so as notto interfere with the threaded portion of the body 404. Also, the natureof the deformation of the member 428 will depend on the particulardesign of the member 428. In the position of FIG. 9 the ferrules 408,410 achieve grip and seal of the conduit T. Further note that thedeformation of the member 428 evidences the resistance to additionalrelative axial stroke between the body 404 and the nut 406 after contactis made between the surfaces 430 and 432.

FIG. 10 shows the fitting 400 in a FTP preparatory to a remake followinga loosening or disassembly of the fitting 400 from a prior pull-up suchas the initial pull-up of FIG. 9. Note that in this FTP the back ferrule410 and possibly the front ferrule 408 exhibit a spring back when thenut 406 is loosened from the body 404 during disassembly. This springback is typical particularly during the first several remakes of thefitting. The spring back is evidenced by a gap Si between the forwardportion of the back ferrule 410 and the indentation in the conduit Tcaused by the back ferrule grip of the conduit in the pulled-upcondition. Note further that the member 428 has retained its deformedstate from the prior pull-up due to plastic deformation. There may besome elastic deformation as well but it is the plastic deformation thatfacilitates remake by torque. As a result of the plastic deformation ofthe member 428, there is a gap G2 between the distal end surface 430 ofthe member 428 and the contacting surface 432 of the body 404. Furthernote that the gap G2 will be smaller than the gap G1 because after theinitial pull-up of the fitting 400 the ferrules 408, 410 have alsoplastically deformed (as has the conduit T) and taken a plastic set sothat the overall axial length of the fitting 400 has been compressed andshortened. The difference between G1 and G2 also evidences the fact thateach successive pull-up or remake of the fitting 400 requires lessrelative axial stroke between the body and the nut to effect conduitgrip and seal.

FIG. 11 illustrates the fitting 400 after the remake from the FTPposition of FIG. 10. Note that in comparison with FIG. 9 the member 428has become more axially compressed and deformed by the buckling action,and that the ferrules 408, 410 are returned to a position for conduitgrip and seal. The gap G2 has been reduced on remake again to zero. Thesame torque may be used for the remake as was used for the initialpull-up, or a different torque may be used as needed.

FIG. 12 illustrates the fitting 400 in another FTP position prior toanother remake after the nut 406 again was loosened from the body 404.Note that there may be a spring back of the ferrules 408, 410 althoughit is not noticeable, and with each remake becomes less and less as theferrules plastically deform towards their maximum extent. Also note thatthe member 428 has taken a further plastic set due to the prior pull-upplacing the member 428 under axial compression or axial load. As aresult, in the FTP preparatory to another remake, there is a gap G3between the end surface 430 of the member 428 and the contacting surface432 on the body 404. The gap G3 will be smaller than the gap G2 of theprior pull-up due to the further axial compression and plastic set ofthe member 428.

It will be noted that with each pull-up the plastic deformation of themember 428 in effect produces a shorter axial length of the member 428.For example, in the FTP prior to initial pull-up the member 428 may havea length X. After an initial pull-up, presuming that the initial pull-upinvolved axial compression of the member 428, the member will have anaxial length of X-Y where Y represents the reduction in axial lengthcaused be the plastic set and axial compression of the member 428 duringinitial pull-up. After a remake, the member 428 may have an axial lengthof X-Y-Z where Z represents an additional reduction in axial length ofthe member 428 following another pull-up during remake of the fitting.

FIG. 13 shows the fitting 400 after the remake from the FTP position ofFIG. 11. Again, the gap G3 has been reduced to zero as the body 404 andthe nut 406 are further axially advanced together relative to eachother. Note further the additional deformation of the member 428.Successive remakes and deformation of the member 428 show pronounceddeformation and effect of the creases 438 a and 438 b. Again, the remakemay be to the same or different torque as the prior pull-ups.

It should also be noted that any of the remakes may alternatively bemade by turns rather than torque, as with the initial pull-up. Bothtechniques may be used throughout the life of the fitting 400.

A comparison of the change in the gap between the member 428 and thecontacting surface 432 of the body illustrates another useful aspect ofthe member 428. Comparing FIGS. 7 and 8, or FIGS. 10 and 11, forexample, when the gaps G1 and G2 are reduced to zero, there is avisually perceptible effect that indicates or gauges that pull-up hasbeen completed. This is particularly so for an initial pull-up in whichthe member 428 is designed to make contact with the body 404. Therefore,the gaps G1, G2 and G3 that are present in the FTP positions prior to apull-up provide the ability to visually confirm, or in other words themember 428 functions as a gauge, that pull-up has been achieved when thegap reduces to zero. With many remakes the FTP gap becomes smaller andsmaller so that depending on the particular design of the member 428 andthe fitting 400, the visual indication and ability to gauge may only beused or needed for a selected number of remakes, for example fiveremakes. But nonetheless, the member 428 provides a means and techniquefor visual verification that pull-up has been completely for the initialpull-up as well as remakes.

Although in the embodiment of FIGS. 4-13 we use the torque collar 402for pull-up by torque of the fitting 400, and the torque collar 402 alsomay be used as a gauge to confirm pull-up was completed, separately wenote that the member 428 may be used as a gauge only, regardless ofwhether the member 428 is also used as a torque collar for pull-up bytorque. The member 428, whether integral as in FIGS. 4-13 or as aseparate piece as described below, may be used as a gauge for a visualconfirmation of initial pull-up and remakes for many different fittingdesigns, including non-metal fittings as well as fittings that arepulled-up or tightened to a final condition without a threadedconnection. An example of a non-threaded mechanical connection for aconduit fitting is a fitting that is pulled-up by a clamping device. Theusefulness of the member 428 as a gauge for pull-up indication derivesfrom the incremental plastic deformation that occurs with each pull-upand remake.

The above description of an exemplary remake process is an availableremake technique in which the body 404 and the nut 406 are rejoined tothe FTP and then snugged up to further deform the member 428. The torquecollar 402 provides another alternative way to remake the fitting 400.In an alternative remake process, the body 404 and the nut 406 arerejoined to the FTP and then further tightened until the distal end 430contacts the contacting surface 432 of the body 404. This position isevidenced by the gap G being reduced to zero. This position wouldcorrespond to the just prior pulled-up position of the fitting 400. Thebody 404 and the nut 406 are then snugged up for an additional partialturn, for example a 0.125 partial turn although this amount will dependin part on how many remakes are made because the additional strokeconsumed during remakes becomes smaller as the number of remakesincreases. By using the gap G to determine return of the fitting to thejust prior pulled up position, the additional snug up partial turn maybe controlled and less stroke may be needed to snug up the body and nutto complete the remake. This alternative remake process may also be usedwith the non-integral torque collar embodiments described hereinbelow.The alternative remake process may be used with each of the remakes ofthe fitting if so desired.

FIGS. 14-22 illustrate another embodiment of a fitting 450 with a torquecollar 452. In an embodiment, the torque collar 452 is a separate anddistinct part of the fitting 450, as distinguished from the embodimentof FIGS. 4-13 in which the torque collar 402 is an integral part of thenut 406. As will be apparent, the torque collar 452 may be designed tooperate in a manner similar to the embodiment of FIGS. 4-13. Like theembodiment of FIGS. 4-13, the torque collar may be axially fixed to athreaded fitting component (e.g., the threaded nut), but instead ofbeing integral with the fitting component, the fitting component and thetorque collar are retained together as a discontinuous subassembly orpreassembly. In other embodiments (not shown), the torque collar may beloosely received between first and second threaded fitting components,with end portions of the torque collar engaging corresponding bearingportions of the first and second fitting components.

Like parts are labeled with like reference numerals as the embodiment ofFIGS. 4-13 and will not be repeated. The torque collar 452 may berealized in the form of a ring 454 that may be separate from oralternatively may be attached to or joined with the nut 456. The torquecollar 452 includes a stroke resisting member 458 that may be but neednot be the same as the stroke resisting member 428 except that themember 458 extends from the ring 454 rather than from a portion of thenut. The member 458 may be designed to plastically deform, such as witha buckling effect for example or other plastic deformation, in the samemanner as described above.

In the embodiments of FIGS. 14-22, 25, and 26, we show the torque collar452 as being mechanically connected to the nut 456 with a cartridgefeature that will be described hereinbelow. Alternatively, the torquecollar 452 may be a free standing component and will still function in asimilar manner.

The use of a separate torque collar 452 may provide a gauge feature inthat until the torque collar 452 makes contact with the nut 456, thering 454 can freely be made to spin or rotate about the X axis. Aftercontact is made with the nut 456, the exemplary ring 454 is no longerfreely rotatable or no longer freely spins, and therefore provides agauge or visual indication that a complete pull-up has been performed.The member 458 presents a gap G with the nut in the FTP that may alsoprovide a gauge indication as above. The gap G that is present in theFTP for initial pull-up and remakes allows the ring 454 to freely spin,wherein after pull-up or remake the gap is consumed by contact betweenthe ring 454 and the body 404 so that the ring no longer freely spins.Thus the spin/no spin feature may alternatively be used to gauge thefitting 450 for each pull-up including the initial pull-up and one ormore remakes that provides a gap G at the FTP. So long as the gap G atthe FTP before each remake is greater than zero, the separate ringconcept may be used to gauge pull-up. An outer surface or portion 454 aof the ring 454 may be knurled, roughened or otherwise treated tofacilitate spinning rotation of the ring 454.

In an alternative embodiment, the stroke resisting member 458 may beprovided as an integral part of the nut 456 (as in the embodiment ofFIGS. 4-13 herein) but the ring 454 (without an attached strokeresisting member) may be a separate non-integral component. FIG. 30illustrates just one example of such an arrangement. This alternativeembodiment provides the same assembly by torque functionality if sodesired and also allows the ring 454 to provide the gauging function orindication of completed pull-up based on whether the ring 454 can freelyspin or not.

Referring back to FIG. 14, the member 458 has a first or proximal end orproximal ring portion 458 a and a second or distal end or distal ringportion 458 b. The member 458 may include a first cylinder portion orfirst axially extending wall portion 460 having an inner diameter D3 anda second cylinder portion or second axially extending wall portion 462having an inner diameter D4. D4 may be greater than D3 in theembodiment, however, the opposite may be used or the diameters may bethe same. The outer diameters of the first and second wall portions maylikewise vary with respect to each other. A web 464 joins the firstcylinder portion 460 with the second cylinder portion 462, and the webmay be angled with respect to each of the first and second wall portionsto define a hinge portion, by use of the same radius transitions 464 a,464 b to form creases to facilitate buckling or other desireddeformation of the member 458 under axial load or axial compression. Thefirst and second wall portions and the web may be provided with radialthicknesses that are smaller than corresponding radial thickness of theproximal and distal ring portions, for example, to facilitate bucklingor other such controllable deformation. In one embodiment (not shown),the distal ring portion may have a radial thickness that issubstantially the same as the second wall portion. In still otherexemplary embodiments, the first and second axially extending wallportions may extend at an angle with respect to a central axis, suchthat the inner and outer diameters of the first and second wall portionsvary, for example, to facilitate buckling or other such controllabledeformation in response to an axial load.

FIG. 14 is comparable to FIG. 7 and illustrates the fitting 450 at theFTP prior to the initial or first time pull-up. Note that the gap G1 isprovided as in the previous embodiment (the conduit T is not shown inFIG. 14). FIG. 15 is comparable to FIG. 8 and shows initial contactbetween an end surface or bearing surface 466 of the distal end 458 b ofthe member 458 and a radially extending contacting surface 432 of thebody 404, wherein the gap G1 has been reduced to zero. This figure mayrepresent either contact at the full pulled-up position or just prior tothe full pulled-up position as noted above. In either case, furtherrelative axial stroke between the body 404 and the nut 456 produces anaxial load or axial compression on the member 458. FIG. 16 is comparableto FIG. 9 and illustrates an example of a completed initial pull-upposition in which there has been deformation of the member 458. FIG. 17is comparable to FIG. 10 and illustrates a FTP prior to a remake of thefitting 450. The gap G2 is smaller than the gap G1 because of theplastic deformation of the member 458. The ferrules 408, 410 alsoexhibit some spring back. FIG. 18 is comparable to FIG. 11 andillustrates the fitting 450 after pull-up for a remake of the fittingfrom the FTP of FIG. 17. The member 458 has been further deformed byaction of the buckling of the web 464. FIG. 19 is comparable to FIG. 12and illustrates a FTP prior to another remake subsequent to the remakeof FIG. 18. The member 458 has been further deformed and the gap G3 issmaller than the gap G2 due to less spring back of the ferrules 408,410.

Although the torque collar 452 is a separate and discrete part fromeither of the fitting components 456 and 404, we provide an embodimentfor connecting or cartridging the torque collar 452 to the nut 456. Weuse the terms “cartridging” and “cartridging process” interchangeablyherein to refer to the act or steps of joining a first fitting component(e.g., a torque collar or a front ferrule) with a second fittingcomponent (e.g., a fitting nut or a back ferrule) to form a cartridgedsubassembly or pre-assembly. A similar technique may be used to connectthe torque collar 452 alternatively to the body 404. Other structuresand techniques may be used as needed.

With reference to FIGS. 20-22 we illustrate steps in the cartridgingprocess as well as the cartridge structure. These figures are enlargedviews of the mechanical connection or cartridge structure 467 betweenthe torque collar 452 and the nut 456 in FIGS. 14-19. The nut 456 mayinclude a cartridge feature in the form of an annular extension 468having a radially outward rib 470. This rib 470 is received in a recess472 formed in a rearward portion of the ring 454. This rearward portionmay include a cartridge feature 469 in the form of a radially inwardextending hook, barb, or other such protrusion 474 and the recess 472.In the position of FIG. 20, the rib 470 is being axially inserted intothe recess 472 through an opening 476 that is delimited by the minorinside diameter of the hook 474. The major outside diameter of the rib470 is greater than the minor diameter of the opening 476 so that thereis an interference to pushing the rib 470 past the hook 474. Asillustrated in FIG. 21, this interference causes the rib 470 to push onthe hook 474. The hook 474 and the recess 472 are defined in part by awall 478 that may include a sharp corner (i.e. small radius) or crease480 that facilitates forward (to the right as viewed in the drawing)bending or folding of the hook 474. This deformation of the hook 474enlarges the diameter of the opening 476 enough so that the rib 470passes through the opening 476 and is received in the recess 472. Asillustrated in FIG. 22, the deformed hook 474 preferably undergoes aplastic and an elastic deformation. The plastic deformation facilitatesseparating the torque collar 452 from the nut 456 if so desired aftercartridging the two together. The elastic deformation allows the hook474 to spring back sufficiently so that there is still an interferencewith the rib 470, thus retaining the torque collar 452 with the nut 456with a reasonably robust connection. From FIGS. 14 and 22 it will benoted that the extension 468 may include an end surface 482 that willcontact and push on a portion 484 of the wall 78 that delimits therecess 472 so that the torque collar 452 is axially displaced with thenut 456 during pull-up.

It should be noted that the cartridge feature 469 of the folding hook474 and the recess 472 may be used in other applications other than tocartridge a torque collar to a fitting component, in that it provides acartridge structure and process that may be used to connect two partstogether, particularly metal parts, for example, parts comprisingstainless steel. Therefore, an inventive concept presented herein is fora cartridge feature 469 that cooperates with a mating part to cartridgetwo devices together, and FIG. 20 is an embodiment thereof. The matingpart may be any part that has a second cartridge feature that isretained by the cartridge feature 469—an example of which is a nut withan extension 468 and the rib 470 but such is just one example.

With reference to FIGS. 23-26 we illustrate additional alternativeembodiments for a fitting that uses a torque collar as describedhereinabove (like parts are given like reference numerals). FIGS. 23 and24 provide a fitting 490 that may be but need not be the same embodimentas FIGS. 4-13 of an integral torque collar 402 that may be an integralpart of the nut 406 (or alternatively, but not shown, an integral partof the body 404). FIGS. 25 and 26 illustrate a fitting 502 that may bebut need not be the same embodiment as FIGS. 14-22 of a non-integraltorque collar 452 that may be a separate and distinct part from the nut406 and that either remains a separate third element of the assembly ofthe nut 456 and the body 404, or may be cartridged or otherwise attachedto the body 404 or alternatively to the nut 456. The alternativeembodiments of FIGS. 23-26 incorporate a ferrule cartridge or ferrulesubassembly 492, in which the front ferrule 494 and the back ferrule 496are connected or “cartridged” together with a mechanical connection orretaining structure R, as described in greater detail below. Otherexemplary ferrule cartridge arrangements that may be utilized aredescribed in co-pending U.S. Patent Application Publication No.2010/0148501 (the “'501 Application”), entitled “Ferrule Assembly forConduit Fitting,” and incorporated herein by reference in its entirety.

The alternative embodiments of FIGS. 24 and 26 further incorporate afront ferrule 494 having a convex portion 498 of an outer wall orsurface between the forward portion 422 of the front ferrule and arearward portion 500 of the front ferrule, for example, to facilitateconcentration of radial load forces from the front ferrule to an axiallyinboard portion of the fitting body camming mouth, as described ingreater detail below.

With reference next to FIGS. 27-32B, we present additional alternativeembodiments for the stroke resisting member, for example, the member428, 458 and other embodiments. Although the embodiments of FIGS. 27-32Bare shown for a non-integral design with the torque collar cartridged tothe nut with a cartridge structure 467, these embodiments mayalternatively be used with integral stroke resisting members, as well asnon-integral members that are not cartridged or otherwise mechanicallyconnected or attached to a fitting component such as a body or nut. Thedifferent embodiments (other than FIGS. 30 and 30A) are directlyprimarily to the shape and geometry of the portion of the strokeresisting member that undergoes deformation resulting from the memberbeing axially compressed or loaded during pull-up and remake. In otherwords, various portions of the member that are between the proximal endand the distal end of the member. In the various embodiments, a fittingmay include a body 404, a nut 406, and one or more ferrules such as afront ferrule 408 and a back ferrule 410 as in the embodiments describedabove, which may function in a similar manner, although other designsmay be used (like reference numerals are used for like parts in theabove described embodiments for convenience). Therefore, the descriptionof FIGS. 27-32B is directed to the geometry of the stroke resistingmember and not repeat the description of the other parts of the fitting.All of FIGS. 27-32B illustrate a fitting that is in the FTP and do notshow the conduit as yet inserted.

An embodiment is illustrated in FIGS. 27, 28 and 28A. The strokeresisting member 510 may include a generally W shaped profile incross-section with a middle web portion 512 having an inverted Vprofile. An inboard leg 514 of the V portion 512 may blend (e.g., with aradius portion 516) at an axially extending first wall portion 520 to aproximal ring portion 518 at a proximal end of the member 510. Anoutboard leg 522 of the V portion 512 may blend (e.g., with a radiusportion) at an axially extending second wall portion 524 to a distalring portion or flange 526 at a distal end 528 of the member 510. Thelegs of the V portion are angled with respect to the first and secondwall portions to define a hinge portion. The apex of the V may be formedby an outer radius 530 that joins the outboard leg 522 to the inboardleg 514, and as shown, may be entirely radially outward of the axiallyextending wall portions 520, 524 joined by the web. The legs 514, 522may but need not have a uniform thickness T1, and may be reduced inthickness with respect to the proximal and distal ring portions. Aradially inner surface 532 of the V portion may have a different sizeinner radius 534 from the outer radius 530. The radiuses as well asother portions of the member 510 may be used as hinge points orlocations to facilitate the design and control of the deformation.

Another embodiment is illustrated in FIGS. 29 and 29A. The strokeresisting member 540 may include a web 542 that joins a distal end ordistal ring portion 544 of the member 540 to a proximal end or proximalring portion 546 of the member 540. The web 542 may have a varyingthickness T2 that increases in an inboard direction—for example—anoutboard portion may have a thickness T2′ and an inboard portion mayhave a thickness T2″.

In an embodiment illustrated in FIGS. 30 and 31, we illustrate anembodiment in which an indicator ring 550 is a separate part from thestroke resisting member 552. The stroke resisting member 552 may beintegral with the nut 406 or may be still another separate part that iscartridged to the nut 406. The indicator ring 550 may be cartridged to adistal end 554 of the member 552 using a cartridge structure such as thestructure 467 described hereinabove or other structure as needed. Thestroke resisting member 552 may be but need not be the same as themember 428 in the embodiment of FIGS. 4-13. The indicator ring 550therefore may be used as a gauge in which the ring freely spins when itis not in contact with the contacting surface 432 of the body 404. Notethat the distal end 554 of the member 552 will be driven against aninterior surface 556 of the indicator ring 550 rather than directlyagainst a surface of the body 404.

In an embodiment of FIGS. 32 and 33, the stroke resisting member 560 mayinclude a generally omega or arcuate shaped profile in cross-sectionwith a middle portion 562 having a rounded omega profile. An inboard leg564 may blend with a radius portion 566 to a ring 568 at a proximal end570 of the member 560. An outboard leg 572 may blend with a radiusportion 574 to a flange 576 at a distal end 578 of the member 560. Therounded middle portion 562 may be formed by an outer radius 580 thatjoins the outboard leg 582 to the inboard leg 564. The legs 564, 582 maybut need not have a uniform thickness T3. A radially inner surface 584of the middle portion may have a different size inner radius 586 fromthe outer radius 580. The radiuses 566, 574 and 580 as well as otherportions of the member 560 may be used as hinge points or locations tofacilitate the design and control of the deformation.

In an embodiment of FIGS. 34, 35A and 35B, a stroke resisting member 590may include a generally W shaped profile in cross-section with a middleportion 592 having an inverted V profile, somewhat similar in generalshape to the embodiment of FIG. 28 but among other things the W shape isless pronounced radially. An inboard leg 594 may blend with a radiusportion 596 to a ring 598 at a proximal end 600 of the member 590. Anoutboard leg 602 may blend with a radius portion 604 to a flange 606 ata distal end 608 of the member 590. The legs 594, 602 differ from theembodiment of FIG. 28 in that the legs have a somewhat scallopedappearance due to a more complex geometry. Each leg 594, 602 may includeone or more radius portions 610 and tapered portions 612 to provideadded design options to control deformation of the member 590 underaxial load or compression. The legs may be identical with each other butneed not be identical. The scalloping effect allows a designer toselectively position more or less material where needed to controldeformation of the member 590.

In the embodiments of FIGS. 4-35B, the stroke resisting member or torquecollar provides an axially deformable stroke limiting feature having anaxial length that is altered by buckling, collapsing, folding, orotherwise compressing a plastically deformable web portion of the torquecollar disposed between a body driven portion of the torque collar and anut driven portion of the torque collar. This plastic axial deformationresults in axial movement of a radially extending surface that engagesan axially advancing surface of one of the fitting body and the fittingnut during pull-up. In other embodiments of the present application, astroke limiting arrangement may provide for other types of plastic axialdeformation, as opposed to the primarily radial plastic deformation ofthe “dynamic wedge” torque collar embodiments of the above incorporated'705 Application. For example, co-pending U.S. Patent ApplicationPublication No. 2012/0005878, entitled “Conduit Fitting with FlexibleTorque Collar,” and incorporated by reference herein in its entirety,describes fittings having a radially extending flange that isplastically bendable in an axial direction for axial movement of aradially extending surface that engages an axially advancing surface ofone of the fitting body and the fitting nut during pull-up.

According to another aspect of the present application, a strokelimiting arrangement may include internal fitting componentsinteroperable to provide a similar increase in torque during pull-up,configured to correspond with a predetermined axial advance of the nut.The internal stroke limiting arrangement may include internal orenclosed features of one or more of the fitting body, nut, conduitgripping devices, or some additional component assembled within thefitting assembly to provide a torque increase corresponding to apredetermined axial advance of the nut.

We therefore provide in some of the embodiments herein a strokeresisting or limiting member or load bearing member that is associatedwith at least one of two or more ferrules or conduit gripping devices,with the stroke resisting member having a surface that engages a surfaceof another conduit gripping device during relative axial displacement ofthe threaded fitting components during pull-up. The stroke resistingmember may be integrally formed with at least one of the two or moreconduit gripping devices. Alternatively, the stroke resisting member maybe assembled with at least one of the two or more conduit grippingdevices, for example, by loose assembly in an axial sequence of conduitgripping devices in the fitting assembly, or by cartridging with aconduit gripping device. The engaging surfaces initially engage eachother preferably to either coincide with or closely correspond to therelative axial displacement of the threaded fitting components that maybe associated with the number of complete and/or partial turns pastfinger tight position for complete pull-up had the fitting beenpulled-up alternatively by turns. In this way, a fitting can beoptionally pulled-up by turns, by torque or both. Depending on theapplications and criticality of the pull-up process, we do not requirein all situations that the surfaces engage precisely at the point of theprescribed relative axial displacement past the reference position.However, for repeatable and reliable pull-ups, it is preferred that thesurfaces engage in close alignment with the corresponding relative axialdisplacement used for pull-up by turns. In other words, it is preferredbut not required in all cases that the surfaces engage or make contactwith each other upon tightening of the fitting components to a relativeaxial displacement that closely aligns with the prescribed number ofturns and partial turns past the reference position. In this manneralso, the amount of stroke used during any pull-up may be controlled soas to maximize or optimize the number of useful remakes of the fitting.

In the exemplary embodiments, when the surface of the stroke resistingmember of the one conduit gripping device engages the surface of theother conduit gripping device, the manual assembler preferably willsense a distinct increase in the torque required to continue tighteningthe fitting components together. But alternatively, when using a torqueapplying tool, such as a torque wrench, the tool may be used to effectthe same pull-up although the assembler may not necessarily sense thetorque increase.

FIGS. 36 and 37 illustrate a fitting assembly 300′ before and after aninitial completed pull-up in which conduit grip and seal is effected.Similar to the other fitting assemblies described herein, the fittingassembly 300′ includes a body 302′, a nut 304′, a first or front ferrule306′ and a second or back ferrule 308′, that may, but need not functionas described in greater detail above. The front ferrule 306′ includes astroke resisting member or extension 310′ that is sized and oriented tocontact a flanged rear portion or bearing surface 309′ of the backferrule 308′ to effect pull-up by torque in a manner that may, but neednot, be similar to the embodiments of FIGS. 1-35B herein. The retainingmember or stroke resisting end surface and the back ferrule bearingsurface may be substantially radially aligned, such that at least amajority of the stroke resisting end surface is radially aligned with atleast a majority of the back ferrule bearing surface. The strokeresisting member 310′ and back ferrule flange 309′ may be configuredsuch that contact between these components coincides with apredetermined relative axial position resulting from displacement orstroke of the nut 304′ and body 302′ during pull-up. This coincidingpull-up stroke may be prescribed, for example, to assure conduit gripand seal on initial pull-up and/or on one or more subsequent remakes ofthe fitting. The axial compression or load on the stroke resistingmember 310′ produces or is accompanied by an increase in the torquerequired to continue to pull-up the fitting 300′ (i.e., continue toapply torque for relative rotation of the body and the nut), and thistorque increase is significantly greater than would be presented if thecontact and axial load or compression did not occur (i.e., greater thana torque rise associated with axial compression and deformation offerrules of a conventional fitting). Note that there may also be radialloads applied to the stroke resisting member 310′.

Accordingly, the prescribed pull-up stroke may be effected either bycounting turns and partial turns past the finger-tight position as isknown, or alternatively through pull-up by torque using a prescribed orpredetermined torque that results from contact between the strokeresisting member 310′ and back ferrule flange 309′ (and the resultingaxial loads therebetween) occurring at a known axial advance of the bodyand nut together to the prescribed pull-up stroke.

Similar to the torque collars of the embodiments of FIGS. 1-35B, thestroke resisting member 310′ may be configured to plastically deformsuch that the fitting 300′ may be remade using a prescribed torque orturns. Initial pull-up and remakes may optionally be carried out usingthe same prescribed torque or different torque values.

The flexibility and design of the stroke resisting member 310′ may bedesigned to provide a torque response curve such as the exemplary curveof FIG. 38. This graph illustrates an example of a change in the torqueincrease rate (for example, comparing region A with region B) as notedfrom the dramatic change in slope. The slope changes at a relative axialdisplacement X of the nut and body that corresponds with conduit gripand seal, on initial pull-up and/or after one or more subsequentremakes. For example, this torque rate increase may occur at a strokethat corresponds to approximately 1¼ turns past the finger-tightposition. However, the stroke at which the transition occurs may beselected based on the design of the conduit fitting. For example, somefittings are pulled up with 1½ turns past finger-tight position. Also,the torque increase may actually begin (i.e. contact between the strokeresisting member 310′ and the back ferrule flange 309′) after the strokereaches the prescribed pulled-up position by turns so thatidentification of a prescribed torque is assured of resulting in thefitting being tightened to a completed pulled-up position.

In other embodiments contemplated by the present application, a fittingmay be provided with multiple stroke limiting arrangements selected, forexample, to provide a desired magnitude or timing of torque increaseduring fitting pull-up and/or remake. For example, a fitting designermay wish to utilize a stroke resisting member (e.g., one or more of thetorque collars of FIGS. 1-35B described above) in a material or designthat provides for greater flexibility, for example, to facilitate use ofthe torque collar for visual or other intrinsic gauging. This increasedflexibility may result in a less pronounced increase in torque duringfitting pull-up. To insure a clearly identifiable, sharp increase intightening torque, a second stroke limiting arrangement (e.g., thestroke limiting ferrules of FIGS. 36 and 37, described above) may beutilized to further add to the resulting torque at the position ofbody/nut axial advancement corresponding with fitting pull-up. In suchan embodiment, first and second stroke resisting arrangements (forexample, as described above) may be configured for axial compression atapproximately the same relative axial position of the fittingcomponents. As another example, a fitting designer may wish to provide afitting that experiences a first increase or spike in pull-up torqueassociated with initial fitting pull-up, and a second (e.g., larger)increase or spike in pull-up torque associated with one or moresubsequent remakes. A first stroke limiting arrangement (e.g., thestroke limiting ferrules of FIGS. 36 and 37, described above) mayprovide for the first increase in torque at a first relative axialposition of the threaded fitting components, and a second strokelimiting arrangement (e.g., one or more of the torque collars of FIGS.1-35B described above) may provide for the second increase in torque ata second relative axial position, axially advanced beyond the firstrelative axial position. In one such embodiment, the second strokelimiting arrangement may provide a second increase in torque at a secondrelative axial position of the threaded fitting components thatindicates that a maximum number of remakes has been performed. Inanother exemplary embodiment, the external stroke limiting arrangement(e.g., torque collar) may provide the first increase in torque and theinternal stroke limiting arrangement (e.g., stroke limiting ferrules)may provide the second increase in torque.

Another significant feature of some of the inventions herein is theprovision of a retaining structure by which two or more conduit grippingdevices (for example, a ferrule set) are retained or held together as adiscrete unit, subassembly or cartridge, prior to assembling the unitwith fitting components to form a complete fitting. By “cartridge” wemean a group of parts retained together as a discontinuous unit,subassembly or preassembly. We therefore use the terms cartridge, unit,subassembly and preassembly synonymously herein in the context of adiscontinuous structure. We also use the term “ferrule cartridge” or“conduit gripping device cartridge” interchangeably to refer to a unitor subassembly made up of at least two ferrules or conduit grippingdevices held together as a discrete or standalone unit. In particular, a“ferrule cartridge” includes two or more ferrules held together as adiscrete unit or subassembly, and may include additional parts, forexample, seals. Thus, a ferrule cartridge may provide a complete ferruleset for a fitting.

We use the term “discontinuous” to describe the conjoined nature of thecartridge or preassembly in the sense that the two or more conduitgripping devices are manufactured as separate and discrete componentsand remain separate and discrete components, although in accordance withthe inventions herein these parts are retained together as a discretecartridge, subassembly or preassembly, and further wherein afterassembly or even a complete pull-up the parts remain discrete and may bedisassembled into their constituent discrete parts if so desired. Thusthe terms “discontinuous” or “conjoined” are used herein to distinguishfrom fitting designs in which two conduit gripping devices are attachedto or made integral with each other and may in some designs break off ordetach from each other during complete or partial pull-up. In adiscontinuous type structure then, as used in this disclosure, the twoor more conduit gripping devices release, disengage or otherwise becomeseparable from each other during either partial or complete pull-upwithout requiring a fracture, shear or other separation of material. Insome of the cartridge or subassembly embodiments herein, however, anadhesive may be used as part of the retaining structure. Despite theinitial assembly as a cartridge, the conduit gripping devicesindividually perform as designed and the retaining structure does notinterfere with operation and performance of the conduit gripping devicesduring pull-up. The terms “discontinuous” or “conjoined” are furtherintended to include broadly the idea that the two or more conduitgripping devices may be loosely or alternatively snugly retainedtogether as a discrete subassembly. The term “connect” and variationsthereof as used herein with respect to the discontinuous cartridge meansthat the conduit gripping devices are initially formed or manufacturedas separate, discrete and distinct parts, and then held together in adiscontinuous manner as a cartridge or subassembly so as to be able tobe easily joined with fitting components (for example, a nut and body)to form a fitting assembly, but further that the conduit grippingdevices will otherwise retain their expected form, fit and functionwithout interference from the retaining structure.

As an overview of the inventive concepts disclosed herein, there are anumber of characteristics for a discontinuous ferrule cartridgeretaining structure that preferably but not necessarily in all cases aredesirable. These characteristics may in some applications involvetradeoffs as to which ones may have greater significance in overallfitting performance and use as will be apparent from the followingdiscussion. This list is not intended to be an exhaustive list of allcharacteristics, and one or more of the ones discussed herein may not benotable or needed for specific applications.

One characteristic we refer to as a reasonably robust connection or RRC.By RRC we mean that the retaining structure is designed such that theconnected conduit gripping devices will not easily come apart withnormal handling, either individually or bulk, during subassembly,inventory, and subsequent assembly with fitting components to form afitting assembly. The terms “normal” and “easily” as used hereinintentionally indicate that the degree to which the ferrule cartridgedoes not come apart during use is a matter of design choice. But tobetter understand those terms, we view “normal” handling as any handlingof the ferrule cartridge that can be expected or likely to happenthroughout manufacturing, assembly and use of the ferrule cartridge.This may include handling by manufacturing personnel, inventorypersonnel, shipping personnel and end users. It can be expected thatduring such normal handling a ferrule cartridge may be exposed to forcesthat could tend to knock the conduit gripping devices loose or evenseparate. For example, the ferrule cartridge may be accidentally droppedfrom several or many feet onto a hard floor or against a hard object orsurface at various installations or manufacturing/assembly stages. Thedesigner may determine the level of force that the ferrule cartridge canwithstand without damage to the parts or separating or loosening asneeded. Normal handling therefore would not include the use of excessiveor damaging force to attempt purposely to separate the conduit grippingdevices. However, the designer may choose to facilitate the option ofbeing able to separate the parts using proper tools and procedures if sodesired. In other words, the designer has the option to determine howeasily the ferrule cartridge may be disassembled into its constituentparts. In some applications, the ferrule cartridge might be designed sothat it cannot be separated without damaging one or more of theconstituent parts, and in other designs the ferrule cartridge may bedisassembled with simple manual force, and a wide range of available“ease” in between.

The aspect of ease of separation of the discontinuous cartridgecomponents also raises the terms disengage, release or separation andderivative forms thereof when used in the context of describing theferrule cartridge. We use these terms interchangeably in two contexts.The first context is the separation or disassembly of the ferrulecartridge into its constituent parts when done prior to installation ofthe connected ferrules or conduit gripping devices into a fitting. Inthe other context, we refer to disengagement, separation or release ofthe ferrules from the retaining structure that will occur during pull-upof the fitting assembly. Now, in this latter context, the fitting isbeing pulled-up so the ferrules are not literally separated from eachother, and in fact are driven together axially so as to deform and gripthe conduit. But we refer to a ferrule or ferrules as releasing ordisengaging from the retaining structure during pull-up to describe thatthe retaining structure no longer holds the ferrules together. Forexample, in the FTP, the ferrules may not be released from the retainingstructure, and an installer could easily back the nut off the body andremove the ferrule set cartridge or subassembly. However, at aselectable axial position of the ferrules relative to each other duringa pull-up operation, the retaining structure will no longer befunctional to hold the ferrules together. Having the ferrules disengageor release from the retaining structure may be used, for example, toavoid rotation of the conduit during pull-up which might occur due totorque transmission from the nut, through the retained ferrules to theconduit. Reference to a ferrule or ferrules releasing or disengagingfrom the retaining structure is intended to convey the idea that theferrules as a subassembly are no longer held together by the retainingstructure. In the illustrated embodiments herein, only one of theferrules is directly disengaged from the retaining structure, forexample, the back ferrule releasing from the extension. But in the sensethat the two ferrules no longer are held together by the retainingstructure, one may consider that the “ferrules” have disengaged becausethe retaining structure no longer functions to hold the ferrulestogether. Therefore, whether we refer to one ferrule or two ferrulesbeing disengaged or no longer held by the retaining structure, theconcept is that the retaining structure no longer holds the two ferrulestogether.

Another characteristic of the discontinuous ferrule cartridge conceptrelates to maintaining a sufficient bore diameter (SBD). By SBD we meanthat the retaining structure does not cause shrinkage or compression ofthe interior bore diameter of any of the conduit gripping devices thatwould adversely encroach on the bore tolerance to allow a conduit to beinserted through the bore. A related characteristic we refer to as axialbore alignment (ABA) by which we mean that the retaining structure doesnot cause an axial misalignment of the conduit gripping devices thatwould adversely encroach on the effective through bore tolerance forinserting a conduit through both devices. ABA may refer to axialalignment of the conduit gripping device bores with respect to eachother or maintaining an axial through bore for each conduit grippingdevice (in other words, not adversely bending or deflecting a conduitgripping device so as to deform a portion of its bore off-axis).

Another characteristic of the discontinuous ferrule cartridge concept ispreferably to maintain proper finger tight contact (FTC) when thecartridge is assembled into a fitting to a finger-tight position.Fittings are commonly assembled first to a finger tight position (FTP)by which the various parts are assembled onto a conduit in a fairlyloose manner and then snugged up manually without enough force to deformthe conduit gripping devices but with sufficient force to assure FTC.For example, in an exemplary embodiment, FTC means that there is axialcontact between the front portion of the front ferrule or conduitgripping device with the tapered camming surface of the body; axialcontact between the front portion of the back ferrule or conduitgripping device and the camming surface of the front ferrule; and axialcontact between the drive surface of the nut fitting component, and thedriven surface of the back ferrule or conduit gripping device. It isusually desirable, although not necessarily required in all cases, thatthese axial contacts are present in the FTP. An assembler can usuallyfeel or sense this complete axial contact by noticing a distinctiveresistance to further manual tightening of the fitting componentstogether.

Another characteristic of the retaining structure for a discontinuousferrule cartridge is preferably to have the retaining structure notadversely interfere with the functional separation of the conduitgripping devices or the form, fit and function of the conduit grippingdevices during pull-up, thereby permitting each conduit gripping deviceto interact with the body and nut and each other to effect conduit gripand seal. We refer to this characteristic as maintaining two ferrulefunction (TFF), it being understood that none of these characteristicsare limited by the term “ferrule” and not limited to only use of twoconduit gripping devices.

Next we will discuss three types of discontinuous ferrule cartridgeconnection embodiments that are directed to the above notedcharacteristics. It will be readily apparent that some of theseembodiments achieve one or more of the characteristics, perhaps tovarying degrees, thus providing a designer with a number of choices. Butalternative embodiments will be available that do not necessarilyachieve any of the above characteristics or to lesser degree, yet stillbeing within the scope of the claimed inventions. The types are notnecessarily presented in any preferred order. We then will describeexemplary embodiments of each type. Although the descriptions referenceferrules, the inventions may be used with other conduit gripping devicesother than just those known or referred to as ferrules.

The first type (Type 1), we refer to as a radial compression connection.In one embodiment, a retaining structure is provided that may berealized in one example in the form of a flexible portion of the frontferrule that protrudes axially from the back end of the front ferrule.This flexible portion may be integrally formed with the front ferrule orattached thereto. A forward portion of the back ferrule may be press fitinto the flexible portion of the front ferrule to hold the two ferrulestogether as a ferrule cartridge or subassembly. The protrusion ispreferably flexible enough to allow the back ferrule to be inserted asufficient distance to provide a reasonably robust connection, butwithout radially compressing the back ferrule beyond an acceptable SBD.In press fit configurations of the prior art, the press fit operationcould radially compress the rear device so as to adversely affect thethrough bore, or at least there is no control over the amount of radialcompression other than to use special fixturing and control duringassembly. Use of a flexible portion allows the designer to strike abalance between having an adequately robust connection without adverselyaffecting the SBD, allowing easier assembly of the parts. This isbecause the flexible portion may be used so that ferrule deformationduring the press fit operation is taken up by the flexible member andnot the body of the front or back ferrule. In this manner, the flexibleportion does not interfere with the basic geometry or operation ofeither ferrule.

By having the flexible portion extend axially back from the main body ofthe front ferrule, upon pull-up the retaining structure will notinterfere or adversely affect the operation of either ferrule as to eachother, the conduit or the fitting components. Moreover, unlike the priorart, the retaining structure, in a Type 1 arrangement, used for thepress fit does not need to participate in the form, fit or function ofthe front ferrule as that ferrule relates to the overall fitting. Inother words, the front ferrule may operate the same way whether theextension is present or not. In the prior art designs, the front deviceand in particular the retaining structure remains in contact with theback device and is not separated from the operation of the devicesduring pull-up.

Thus, in a Type 1 design, the first and second conduit gripping devicesor ferrules disengage from the retaining structure at a selectableposition during pull-up. In order that the retaining structure notinterfere or adversely affect the form, fit and function of theferrules, it is preferred although not necessary that the retainingstructure allow the ferrules to disengage or release from the retainingstructure after just a slight axial advance of the back ferrule relativeto the front ferrule, for example, after about 0.01 inch to about 0.015inch of movement of the back ferrule relative to the front ferrule.These are only intended to be exemplary values, it being understood thatthe preference is that the retaining structure no longer hold theferrules together after some pre-determinable displacement of theferrules relative to each other. However, the axial position of the backferrule relative to the front ferrule at which the ferrules becomedisengaged may be selected by the designer as needed for a particularapplication.

The second type (Type 2), we refer to as a controlled axial positionconnection. In one embodiment, a retaining structure provides ahook-like member on the front ferrule that moves over a portion of theback ferrule during assembly of the ferrule cartridge. This movementpositions the hook-like member in such as manner as to significantlyreduce radial load on the back ferrule, but also to axially press theback ferrule contact surface against the front ferrule camming surface.By assuring this axial contact, a robust connection is made with littleor no effect on SBD, and at the same time providing FTC as between theferrules even before the ferrule cartridge is installer into a fitting.This also eliminates axial dead space at the ferrule contact area, whichdead space otherwise would take up some of the pull-up stroke (forexample, when pull-up is carried out based on number of turns). Thisassures that there is no dead space between the ferrules which may bedesirable in some fitting designs. In a Type 2 approach, rather thanusing the hook-like member, the ferrules may alternatively be joinedwith an adhesive as part of the retaining structure in such a manner asto assure no dead space between the ferrules and to further assure metalto metal contact where the contact surface of the back ferrule contactsthe camming surface of the front ferrule, both for FTP and throughoutpull-up. The alternative use of an adhesive also releases the ferrulesduring pull-up and by being positioned out of the contact area betweenthe ferrules, does not adversely affect the operation of the ferrulesduring pull-up. As with Type 1, the Type 2 concept allows the ferrulesto individually perform as designed to achieve the TFF characteristic ifso desired.

The third type (Type 3) we refer to as a loose ferrule connection. Inone embodiment, a retaining structure holds the ferrule together butwithout any significant radial or axial load between the ferrules. Thislooser assembly allows some degree of freedom of movement of theferrules with respect to each other. For example, the ferrules can pivotsomewhat with respect to each other and the retaining structure, andalso freely rotate with respect to each other. The ferrules can alsorotate with respect to each other about a common central axis, thuseliminating any tendency of the connection to induce twist or torqueinto the conduit during pull-up before the ferrules release from theretaining structure. The Type 3 approach may be used to best achieve allfive of the above-mentioned characteristics (RRC, SBD, ABA, FTC andTFF), albeit without controlled axial position because of theintentionally looser connection. As with the Type 1 and Type 2 concepts,the Type 3 concept allows the ferrules to individually perform asdesigned to achieve the TFF characteristic if so desired.

The retaining structure typically will include a first portion that isassociated with one of the conduit gripping members and a second portionthat is associated with the other conduit gripping member. In variousembodiments, the retaining structure may involve cooperating structuralfeatures added to both conduit gripping devices (or alternatively usingan additional part) as compared to what might be the design of thoseconduit gripping devices in a non-cartridge design. In such cases werefer to the retaining structure having two portions. But in otherembodiments, the retaining structure may be a structural featureassociate with one of the conduit gripping devices that utilizes astructural feature of the other conduit gripping device even if thatother device has not been modified to allow for a cartridge design.Therefore, as used herein, the concept of a retaining structure does notnecessarily require that the retaining structure be identified as twodistinct parts. The above incorporated '501 Application describesseveral exemplary ferrule assembly embodiments according to the Type 1,Type 2, and Type 3 concepts described above.

In alternative embodiments, the retaining structure may be a separatepart or element that attaches the conduit gripping devices together, butthe exemplary embodiments herein illustrate retaining structures thatare part of and formed integral with one or alternatively both of theconduit gripping devices. As noted above, the term “connecting” andvariations thereof as used herein with respect to the subassembly meansthat the conduit gripping devices are initially formed or manufacturedas separate and distinct parts, and then joined together in aninterlocking or secured manner so as to be able to be easily installedas a single piece unit into a fitting. This is distinguished from someprior art arrangements in which two conduit gripping devices areintegrally formed together such as machining both devices from a singlepiece of material or attaching a conduit gripping device to another bywelding, for example.

In several ferrule cartridge embodiments of the '501 Application, aflexible extension of the front ferrule flexes or expands radiallyoutward to receive a radial protrusion or crown of the back ferruleduring the cartridging process, with the extension snapping back inwardto retain the front and back ferrules together as a cartridgedsubassembly. In some embodiments contemplated by the presentapplication, a front ferrule may be provided with a flexible extensionhaving an enlarged radially extending flange that provides a hoopstiffness and robustness to the cartridge connection, for example, toreduce or minimize plastic radial outward expansion of the extension.

FIGS. 39-41 illustrate another embodiment of a front ferrule for aconduit fitting 290 having a ferrule cartridge 292. The conduit fitting290 may be but need not include the same conduit gripping and sealingarrangements as the fittings described hereinabove. The conduit fitting290 may be a male or female fitting, with the former illustrated, andinclude a male threaded body 294, a female threaded nut 296 and a frontferrule 298 and a back ferrule 299. Except for the front ferrule 298 thefitting may operate the same as described in the other embodimentshereinabove, the ferrule cartridge 292 may operate the same as describedhereinabove, and the cartridging process may be carried out in the samemanner.

The front ferrule 298 includes a central through bore defined by aninterior bore wall 302. An outer wall 304 extends from a front end 306to a first flange 308. A second flange 310 extends from a rearwardportion 312 of the front ferrule. Between a front radial side 314 of thesecond flange and a back radial side 316 of the first flange is an outerdiameter (OD) recess 318. The second flange 310 may serve as a cartridgefeature of the front ferrule 298 and may include a second recess 320.This second recess 320 may be appropriately sized to provide a Type 1, 2or 3 cartridge connection between the front ferrule 298 and the backferrule 299, as described in greater detail above. A recess wall 322delimits the second recess 320. It will be noted that a crease is notutilized in this embodiment, although optionally there may be oneprovided. The second flange 310 extends outboard from the main body ofthe front ferrule 298 proximate a camming surface 324. A reduced widthweb 326 joins the second flange 310 to the rearward portion 312 of theferrule. This web has a width W that in part may be determined by theradial and axial dimensions of the OD recess 318 as well as the radialand axial dimensions of the second recess 320. The second flange 310also may include a generally radially inward extending retentionprotrusion 328 that functions as a retaining extension to cartridge andretain the back ferrule with the front ferrule. But this retentionprotrusion 328 need not fold over or bend when the back ferrule isinserted into the second recess 320, because the web 326 may be designedto be flexible with sufficient elasticity to absorb the stress of thecartridging process as the back ferrule is inserted into the secondrecess 320.

The retention protrusion 328 provides a radially inner surface 330 thatdefines and delimits the diameter D4 of an opening 332 through which acartridge feature of the back ferrule is inserted, as described hereinabove. For example, the back ferrule may have a crown that is pushedinto and retained in the second recess 320 after cartridging. A chamfer334 may be provided to assist the insertion of the back ferrule.

The web 326 may be thought of as a hinge for the second flange 310 toprovide a pivot region or location 336 about which the second flange maypivot or rotate during the cartridging process, as represented by thearrow 338. This motion may be effected by elastic deformation of the web326 so that after the back ferrule cartridge feature is through theopening 332 the second flange 310 returns to its original unstressedposition, although some plastic deformation may occur. The web 326should be sufficiently elastic to permit cartridging and then returnback close enough to an original position to hold the rear ferrule witha reasonably robust connection.

It should be noted that if a particular design herein presents excessivedeformation from plastic deformation as a result of cartridging, apost-cartridging rolling or crimping step may be used to compress thecartridge feature of the front ferrule back to or sufficiently close toits original state to provide the desired robustness of the ferrulecartridge.

FIGS. 40 and 41 illustrate the ferrule cartridge 292 with the conduitfitting 290 in a finger-tight condition. The first flange 308 may havean inboard facing wall 340 (FIG. 39) that may be used to engage an anvilfor the cartridging process. This also can protect the forward portionof the front ferrule during cartridging. As in the prior embodimentsdescribed herein, upon pull-up of the conduit fitting 290, the backferrule releases from the retaining structure R, and also the retainingstructure R does not interfere with normal pull-up and function of theferrules.

The OD recess 318 on the front ferrule 298 adjacent the second flange310 defines in part the annular hinge web 326 for the second flange andprovides an element of flexibility for ease of the optional snaptogether cartridge operation with the back ferrule. The hinge web 326and the desired flexibility can be controlled by the radial depth andaxial position of the OD recess 318, along with the width W and length Mof the web 326. The material volume of the second flange 310, generallydefined by the ferrule material outboard of the OD recess 318, providesa hoop stiffness and robustness to the cartridge connection. The axialthickness of the retention protrusion 328, set by the material providedbetween the inboard facing portion 322 a of the second recess 320 andthe chamfer 334, provides further control of the ease of back ferrulesnap together insertion and robustness of ferrule cartridge 292.

The diameter D4 of the opening 332 and the radial difference andinterference with the OD of the cartridge feature 206, for example acrown, on the back ferrule, also provides further control of the ease ofsnap together insertion and robustness of ferrule cartridge.

In other embodiments of the present application, a cartridging frontferrule may include a rear retaining extension that instead bends orflexes axially forward during the cartridging process to receive aportion of the back ferrule (e.g., a radial protrusion or crown) into acartridge recess of the front ferrule partially defined by the rearretaining extension. FIGS. 42-56A of the present application illustratesseveral embodiments of ferrule cartridges having a primarily axiallybendable front ferrule retaining extension.

Accordingly in an exemplary method of cartridging first and secondferrules as a discontinuous preassembly, a first ferrule is providedwith a rearward extending retaining member defining an inner radialrecess, with the retaining member including a radially inward extensiondefining a rearward facing camming surface. A second ferrule is alignedwith the first ferrule along a common central axial. The second ferruleis axially pressed against the first ferrule such that a radiallyoutward projection of the second ferrule engages the camming surface ofthe retaining member to axially deform and radially expand the radiallyinward extension, thereby receiving the second ferrule projection in theinner radial recess. At least one of the axial deformation and theradial expansion of the radially inward extension is at least partiallyelastic, such that the radially inward extension snaps into a secondferrule retaining condition after the second ferrule projection isreceived in the inner radial recess.

With reference to FIGS. 42-44, a ferrule cartridge or subassembly 200may include a front ferrule or first conduit gripping device 202 and aback ferrule or second conduit gripping device 204. Exemplary materialsfor the ferrules include metal, for example, stainless steel. A commonmetal for conduit fittings is 316 stainless steel, but other metals maybe used as needed. Although we use the reference numeral 200 todesignate the ferrule cartridge, the general reference 200 may besimilar to the exemplary ferrule cartridges or subassemblies of theabove incorporated '501 Application, namely a cartridge or subassemblycomprising at least a first conduit gripping device and a second conduitgripping device. The back ferrule 204 may be but need not be similar tothe back ferrule designs of the above incorporated '501 Application. Inan embodiment, the back ferrule 204 may include a cartridge feature orgeometry 206 that facilitates a cartridge assembly with the frontferrule 202. By cartridge feature 206 of the back ferrule 204 we mean asurface or structure of the back ferrule that interferes with a surfaceor feature of the front ferrule 202 to retain the ferrules together as aferrule cartridge 200. For example, the back ferrule 204 may be providedwith a radial protrusion or crown 206 at a forward or inboard portion208 of the back ferrule. Other shapes and geometries for the backferrule may be used as needed for particular applications, for example,as set forth hereinabove. An advantage of the crown geometry is that theback ferrule 204 is commercially available from Swagelok, Company,Solon, Ohio. But other back ferrule designs may alternatively be used,for example a ferrule design that already has a feature that cooperateswith the front ferrule 202 to allow cartridging or a feature that isadded to an existing design.

We continue to use the convention adopted above of inboard and outboardto indicate relative direction or ends of a ferrule, with inboardreferring to the ferrule end portion that faces the center of a fitting,in other words the forward or front portion of the ferrule, and outboardreferring to the ferrule end that faces away from the center of thefitting, or in other words the rearward or back portion of a ferrule.This convention is noted on FIG. 42 but applies to all the figures.Also, like components, elements and features are given the samereference numeral as above so that the description need not be repeated.

The front ferrule 202 preferably is a circumferentially continuous bodythat includes a central continuous right cylinder bore 210 that extendsend to end through the entire length of the front ferrule 202. In aconventional fitting, the bore wall 210 a is closely received about aconduit end (T in FIG. 46). The front end 212 of the front ferrulepreferably but not necessarily is rounded. This helps prevent or reducea tendency in some fittings for the front ferrule to bite into theconduit (T); thus improving the ability for the front ferrule to burnishthe outer surface of the conduit to provide an excellent fluid-tightseal upon pull-up of the fitting. The front ferrule 202 also includes afrustoconical tapered outer wall 214 that extends from the front end 212towards the back portion 216 of the front ferrule. The front ferrule 202further includes a camming surface 218 that is typically in the form ofa frustoconical surface although a different geometry for the cammingsurface 218 may be used as needed. The tapered outer wall 214 of thefront ferrule forms a fluid-tight seal against the tapered cammingsurface (258, FIG. 48) of the body (252) upon pull-up of the fitting.

At the rearward portion 216 of the front ferrule 202, a member 220extends outboard from an end surface 222. In an embodiment, the endsurface 222 may be a radial surface as shown, however, such is notrequired. The member 220 provides a retaining structure R that may beused to connect or join the front ferrule 202 and the back ferrule 204together as a cartridge or subassembly 200. The member 220 itself may bethought of as a cartridge feature 220 of the front ferrule 202. In anembodiment, the cartridge feature 220 of the front ferrule may coactwith the cartridge feature 206 of the rear ferrule to provide theretaining structure R. The member 220 may be integrally formed with therest of the front ferrule 202, for example when the front ferrule ismachined, or may be attached to the front ferrule to form a one-pieceintegral structure. Note also that the cartridge feature 206 inalternative embodiments of the back ferrule 204 may be integrally formedwith the back ferrule, or may be attached to or otherwise integratedwith the back ferrule to provide a one-piece integral structure.

The member 220 may include a web 224 that extends outboard from the endsurface 222. The web 224 may be circumferentially continuous or may besegmented (e.g., forming fingers or other such extensions). In anembodiment, the web 224 may extend axially, but alternatively the web224 may have both an axial and a radial component to the direction ofextension from the end surface 222. In an embodiment, the web 224 mayinclude a first part 224 a in the form of a tapered outer wall that at aproximal end is contiguous with the end surface 222, and at a distal endthat is contiguous with a second part 224 b in the form of a cylindricalouter wall. The first part 224 a may blend or transition to the secondpart 224 b with a radiused surface 226 or other geometry. The first part224 a therefore may have a width that tapers to a narrower width of thesecond part 224 b. This geometry is optional but may be used tofacilitate flexing or elastic deformation of the member 220 as needed,and may, for example, provide for a radially outward flexing componentto the deformation of the member during cartridging.

In other embodiments, the web portion of the retaining member may beshaped to minimize or eliminate radial expansion of the retaining memberduring cartridging. For example, with reference to FIG. 42B, in analternative embodiment, a front ferrule 270 may be similar to theembodiment of FIG. 42A but having a different profile on the taperedouter wall 272. In this embodiment, the tapered outer wall 272 may befrustoconical and extends from the front end 274 to a rearward portion276. The tapered outer wall 272 extends to a cylindrical surface 278,and a recess 280 is formed contiguous from the camming surface 282.Alternatively, the surface 278 may be frustoconical, tapered or haveanother geometry or profile. The recess is delimited by a wall 284 andmay be the same as the recess and wall structure of the embodiment ofFIG. 42A. Accordingly, a retaining extension 286 may be provided thatwill exhibit a fold over feature when a back ferrule (not shown) iscartridged with the front ferrule 270. The retaining extension 286 mayinclude a chamfer 286 a. The wall 284 may also have a crease 288 with anangle α at the corner that defines the crease 288. In an embodiment, thefront ferrule retaining extension 286 extends from a radially thicker orstiffer rearward portion 276 of the front ferrule 270 as compared toother embodiments disclosed herein, such as FIG. 42A for example. Thus,the FIG. 42B embodiment may be used to provide an increased RRC becausethe extension will be less prone to radial displacement and thereforemore strongly retain the back ferrule.

Referring back to FIG. 42A, at a distal end of the web 224 may be aretaining extension 228 that in an embodiment may be realized in theform of a radially extending hook, barb, tab or other retainingprotrusion structure that will cooperate with the back ferrule 204geometry to provide the ferrule cartridge 200. In an embodiment, theretaining extension 228 may extend generally transversely from thesecond part 224 b of the web 224. For example, the retaining extension228 may align with a radial line although such is not required. Thelength or radially innermost end surface of the retaining extension 228delimits an opening 230 which the forward portion 208 of the backferrule 204 is pushed through in order to cartridge the front ferrule202 and the back ferrule 204 together. In an alternative configuration,the retaining extension 228 may extend from a different location alongthe web 224 rather than from the distal end of the web as illustrated.

With reference also to FIG. 42A, the member 220, and particularly theweb 224 including the first part 224 a, the second part 224 b and theretaining extension 228, forms a wall 232 that delimits a recess orpocket 234 within the member 220. This recess 234 receives the cartridgefeature 206 of the forward portion 208 of the back ferrule 204. In anembodiment, the cartridge feature may be the crown 206 that is insertedthrough the opening 230 defined by the member 220 so that aftercartridging the crown 206 is positioned in the recess 234 and isretained therein by the member 220, most notably the retaining extension228. The retaining extension 228 may include a chamfered surface 228 athat facilitates aligning the forward portion 208 of the back ferrule204 with the opening 230 during the cartridging process, and alsoreducing possible damage to the back ferrule during cartridging bypreferably not presenting a sharp edge where the back ferrule contactsthe retaining extension 228 at the opening 230.

The wall 232 in an embodiment may have a first part 236 that delimits amajor diameter of the recess 234, and a second part 238 that delimits anoutboard axial extent of the recess 234. The diameter of the wall firstpart 236 is greater than the diameter D1 of the opening 230, both beforeand after the front ferrule 202 and the back ferrule 204 are cartridgedtogether. The axial length of the wall first part 236 and the diameterof the recess 234 defines the pre-cartridge size of the recess 234 thatreceives the cartridge feature 206 of the back ferrule 204. The lengthof the wall second part 238 also delimits the initial or unstresseddiameter of the opening 230. In order to facilitate cartridging byinserting the back ferrule cartridge feature 206 through the opening230, we provide a structure or means by which the retaining extension228 can be deformed in a controlled manner. By controlled manner we meanthat the deformation occurs in a predictable way during normalcartridging. In an embodiment, this controlled deformation of theretaining extension 228 may be realized in the form of a folding orbending of the retaining extension 228 in a forward or inboard directionas the back ferrule cartridge feature 206 is pushed through the opening230. This deformation may be partially elastic and partially plastic, inthat some spring back of the retaining extension 228 after the cartridgefeature 206 clears the opening 230 and is received in the recess 234 maybe used to keep the back ferrule 204 retained with the front ferrule 202as a ferrule cartridge 200. The effect of plastic deformation is thatthe retaining extension 228 remains folded or bent forward aftercartridging is completed.

In an embodiment, a structure we use to provide a controlled deformationof the retaining extension 228 during the cartridging process is acrease 240 at the joint between the retaining extension 228 and the web224. This crease 240 provides a hinge function or operation thatfacilitates folding or bending the retaining extension 228 forward witha controllable and predictable deformation to allow the back ferrule 204to be cartridged with the front ferrule 202 without damaging the backferrule 204 while still maintaining a desired level of RRC.

The crease 240 may be defined by a corner between the wall first part236 and the wall second part 238, in which the corner is delimited by anangle α. In an embodiment, the wall first part 236 may be substantiallycylindrical along the axis X and the wall second part 238 may be on aradial line so that α may be a right angle. More preferably, the angle αprior to cartridging is preferably approximately 93°±3° and morepreferably is approximately 90°-92° or in other words slightly obtuse.By using an angle α that is slightly obtuse prior to cartridging (inother words in an non-deformed condition), the corner or crease 240 iseasier to machine. But, it is preferred that the angle α in thenon-deformed condition not be too much greater than 95° otherwise theretaining extension 228 may not deform properly and may cause undesiredbuckling or possibly excessive outward flaring of the member 220.Alternatively, after the crease 240 is machined, a tool may be used topre-stress or pre-bend the retaining extension 228 forward so as to formangle α to be a right angle or even an acute angle before the backferrule 204 is pushed against the retaining extension 228 as part of thecartridging process. Regardless of the initial angle α, after thecartridging process is finished, the angle α will be an acute angle thatis <90° because of the fold over result of the retaining extension 228.

Alternatively, the wall 232 may have many different shapes and anglesdepending on the nature of the cartridging process that will be used andthe desired robustness of the mechanical connection between the frontferrule and the back ferrule. The wall first part 236 and the wallsecond part 238 may have shapes, geometry or contours that are notcylindrical or frustoconical, but still there may be a definable cornerthat provides the crease 240. For example, the wall first part 236 maybe frustoconical in either an unstressed condition or after cartridging,and the wall second part 238 may be radial or have another geometry orshape so as to provide an acute angle α after cartridging. We have foundthat the use of an acute angle for a after cartridging is preferred andmay be any value less than 90°, for example, in the range ofapproximately 89° to approximately 30°, more preferably approximately85° to approximately 45°, and still more preferred in the range ofapproximately 80° to approximately 60°. However, a right angle for a maybe used but preferably a is not an obtuse angle after cartridgingmeaning a greater than 90°. The angle α after cartridging may berealized with many different dimensions and geometry for the wall firstpart 236 and the wall second part 238.

Although for convenience and clarity we describe the folding or bendingaction as occurring about the crease 240, this does not imply that allof the deformation is only at the crease 240. Other portions of theretaining extension structure 228 may deform either plastically,elastically or both, but the crease 240 provides a pivot or hinge bywhich the deformation and folding or bending can be effected.

With reference next to FIG. 42C, we illustrate in half-longitudinalcross-section another embodiment of a member 350 for a front ferrule202′, which may be an alternative embodiment of the member 220 used witha front ferrule 202 in the other embodiments of FIGS. 42-45. Theembodiment of FIG. 42C may alternatively be used with other frontferrule embodiments, however, and not just with the other embodiments ofFIGS. 42-45. Also, some of the features of the FIG. 42C embodiment maybe used without all of the features being used. FIG. 42C is provided toillustrate design options for providing a retaining extension 352, forexample a hook or barb or other protrusion, that folds over at a creasein a controlled manner during cartridging with a back ferrule.

It should also be noted that the member 350 may be used in otherapplications other than cartridge ferrules, in that it provides acartridge structure and process that may be used to connect two partstogether, particularly metal parts, for example, parts comprisingstainless steel. Therefore, an inventive concept presented herein is fora cartridging member that cooperates with a mating part to cartridge twodevices together, and FIG. 42C is an embodiment thereof. The mating partmay be any part that has a cartridge feature that is retained by thecartridge member 350—an example of which is a back ferrule with a crownbut such is just one example.

The member 350 is illustrated in FIG. 42C in half section, it beingunderstood that the member 350 may be circumferentially continuous oralternatively discontinuous, as well as may be symmetric about the Xaxis. A portion of the full cross-section is shown in phantom lines inFIG. 42C.

The retaining extension 352 at its minor diameter D5 may have a radiallyinward end portion 354 adjacent to a forward facing wall 356 of theretaining extension 352. The radially inward end portion 354, viewed incross-section, may have an axial length (AFL), which may besubstantially flat as shown in FIG. 42C, rounded as shown in FIG. 42A,or otherwise shaped to diverge axially from a rearward camming surface378 of the retaining extension 354. The forward facing wall 356 has aradial length (RHL) extending inward from first wall portion 358 of aweb 360. The first wall portion 358 may be cylindrical but alternativegeometry may be used as needed. Forward facing wall 356 is also referredto herein as a second wall portion 356 that is part of an inner wall(368) that delimits in part a recess as described below.

The retaining extension 354 may extend generally radially from a distalend 362 of the web 360. As in the other embodiments of FIGS. 42-45, theretaining extension 354 forms an angle α at a crease 364 between theforward facing wall portion 356 and the first wall portion 358. Theforward facing wall portion 356 may blend to the cylindrical portion 354with a radius portion 366. In a non-deformed state prior to cartridging,as shown in FIG. 42C, the angle α may be a right angle or near rightangle as in the above embodiments. After cartridging, the angle α willbe acute in that the retaining extension 352 will plastically deform bybending or folding generally about the crease 364. The crease 364 may bea sharp corner as described hereinabove, for example with a small radiusto promote the folding action.

The web 360 includes an inner wall 368 having the first wall portion 358and the second wall portion 356. The inner wall 368 blends into an endwall 370 of the front ferrule 202′, for example with a radius 372. Theinner wall 368 delimits a recess 374 that receives a cartridge featureof the back ferrule (not shown), for example, a crown such as shown inthe above embodiments, or another form of cartridge feature that isretained in the recess 374 after cartridging. The cylindrical portion354 diameter D5 delimits an opening 376 through which the back ferrulecartridging feature (not shown in FIG. 42C) passes during thecartridging process.

Adjacent to the cylindrical portion 354, axially opposite from theforward facing wall 356, may be an optional tapered camming mouth orsurface 378 to assist aligning the back ferrule and front ferrulecenterlines during the cartridging process. The camming mouth 378 blendsto a rearward facing wall 380 of the retaining extension 352. Thecamming mouth 378 may be, for example, a frustoconical surface. Thetaper angle HCMA (which is the half angle as viewed in the drawing) ofthe camming mouth 378 relative to the axis X, viewed in cross section,may be approximately 60° to approximately 15°, preferably approximately50° to approximately 30°, and more preferably approximately 45° toapproximately 35°. The camming mouth 378 has an axial length CML, whichwhen added to the AFL equals the axial width AHW of the retainingextension 352 (AHW=CML+AFL).

The ratio of AFL/AHW may range from approximately 0.8 to approximately0.2, preferably approximately 0.6 to approximately 0.3, and morepreferably approximately 0.5 to approximately 0.4. Correspondingly, theratio of AFL/CML may range from approximately 4.0 to approximately 0.25,preferably approximately 1.5 to approximately 0.43, and more preferablyapproximately 1.0 to approximately 0.66. The ratio of AFL/RHL may rangefrom approximately 1.0 to approximately 0.3, preferably approximately0.8 to approximately 0.4, more preferably approximately 0.6 toapproximately 0.5.

The camming mouth 378 may blend at a forward end with a radiustransition 382 to the inner cylindrical portion 354, and the cammingmouth 378 may blend at a rearward end with a radius transition 384 tothe rearward facing wall 380.

Although the cylindrical portion 354 blends to the forward facing wall356 with the radius transition 366, and also blends to the camming mouth378 with the radius transition 382, nevertheless, the AFL based ratios(as noted above) of the retaining extension 352 may be dimensionedaxially between the end locations 366 and 382 as if the radiustransitions 366 and 382 were zero in value.

With additional reference to FIGS. 43-45, the cartridging process may becarried out using a press A having a drive surface B that applies anaxial force against the back end of the rear ferrule 204; and an anvilor other suitable structure having a support surface C that contacts asuitable surface of the front ferrule 202, which in an embodiment may bea forward facing surface 242 provided by a flange 244 at the rearwardportion 216 of the front ferrule. Alternatively, the support surface maybe surface B and the drive surface may be surface C or both surfaces Band C may be drive surfaces. The press A or other drive surface may beaxially displaced by any suitable drive means, such as hydraulics,pneumatics, manual, electro-mechanical and so on. The cartridgingprocess includes driving the back ferrule 204 and the front ferrule 202axially together along the axis X so as to press the back ferrulecartridge feature 206, for example the crown 206, past the retainingextension 228 and into the recess 234. The diameter of the opening 230in an unstressed condition prior to cartridging is smaller than themaximum or major diameter of the crown 206 to produce an interferencebetween a forward or in-board facing surface (246, FIG. 44) of the crown206 and the retaining extension 228 when the cartridging process begins.Alternatively, other surfaces of the back ferrule 204, for example, anyforward facing surface of the back ferrule 204, may be used. Examples ofother surfaces that may be used are the forward portion 208 of the backferrule such as the nose 206 a or a forward facing surface 206 b of theoutboard flange 204 a of the back ferrule.

Preferably, the cartridging process is aligned as closely as possiblewith an axial relative translation of the back ferrule 204 and the frontferrule 202. This helps to assure that the surface of the forwardportion 208 of the back ferrule that contacts the retaining extension228 makes contact circumferentially and uniformly so that the backferrule 204 is not tilted or off-axis with respect to the front ferrule202 as they are pressed together. Alignment pins or dowels (not shown)between the anvil and the press are one of many options available tomaintain axial alignment of the ferrules 202, 204 during the cartridgingprocess.

As shown in FIG. 43 which is a representation during the cartridgingprocess in which the back ferrule has been approximately insertedhalfway through the opening 230, the initial interference between theback ferrule cartridge feature 206 and the retaining extension 228causes the back ferrule crown 206 to apply a cartridging force againstthe retaining extension 228 which cartridging force causes the retainingextension 228 to be bent or folded forward or inboard by a controlleddeformation in part as a function of the crease 240. This folding orbending deformation of the retaining extension 228 increases thediameter of the opening 230 to allow the crown 206 to pass through, forexample with an optional snap action. This is also an example of a highenergy to low energy connection technique described hereinabove, inwhich during the cartridging process a higher energy is applied to theback ferrule 204 and the retaining structure 228 to push the crown 206into the recess 234, and as soon as the crown 206 clears the retainingextension 228 the rear ferrule 204 is cartridged and retain with thefront ferrule 202 in a lower energy state (for example without radial oraxial load between the rear ferrule cartridge feature 206 and thesurfaces that delimit the recess 234).

FIG. 44 illustrates the ferrule cartridge 200 after the rear ferrulecartridge feature 206 has cleared the retaining extension 228 and ispositioned in the recess 234. Note that the retaining extension 228 isplastically deformed and remains folded over with the angle α an acuteangle, however, the retaining extension 228 may also exhibit elasticdeformation with some spring back so that the final diameter of theopening 230, while greater than the original diameter prior tocartridging, is small enough to provide interference with the crown 206and thereby retain the ferrules together as a ferrule cartridge 200.

FIGS. 44 and 45 illustrate the front ferrule 202 after cartridging withthe folded over retaining extension 228, along with illustrativeexamples of the pre and post cartridging diameters (D1 and D2respectively) of the opening 230. Further note that an inboard facingsurface 246 (FIG. 43) of the crown 206 makes contact with the retainingextension 228 during the cartridging process, but an outboard facingsurface 248 (FIG. 44) may be a surface that interferes with theretaining extension 228 after cartridging is completed. In an embodimentof a back ferrule having a crown 206 as the cartridge feature, the postcartridging diameter D2 preferably is less than the post-cartridgingmajor diameter D3 of the crown 206. For example, preferably but notnecessarily D3 is greater than D2 so that when the cartridged ferrules200 are pivoted or are radially displaced with respect to each other, anobserver cannot visually see (through the post-cartridge opening 230)the surface of the major diameter of the crown 206 through thepost-cartridge opening 230. This result may be used to control the levelof RRC desired for a particular application.

The back ferrule surface 248 preferably although not necessarilycontacts the deformed retaining extension 228 only as an interferenceagainst axial separation and not necessarily in continuous contact. Inother words, it is preferred although not required that the cartridgefeature 206 of the back ferrule that is retained in the recess 234 be aloose retention without axial or radial load. A loose cartridgeconnection allows the ferrules to easily align and self-center axiallyand radially particularly when the conduit T is inserted into theconduit fitting 200 preparatory to pulling-up the fitting. Butalternatively, the cartridge feature 206 of the back ferrule may beunder radial or axial load or both depending on the type of mechanicalconnection needed, including the desired robustness. The amount ofspring back or elastic deformation of the retaining extension 228 andfor that matter the member 220 in general may be designed to provide thedesired robustness of the ferrule cartridge 200. This elasticdeformation may be controlled, for example, by selection of the geometryand materials of the member 220 along with the geometry and materials ofthe back ferrule cartridge feature 206.

Many alternative design criteria may be used to control the deformationof the member 220 including if so desired, the retaining extension 228.The criteria may include, for example, the material of the front ferrule202 as well as surface treatment, the thickness of the web 224 in thevarious parts of the web, the taper angles and so on. The crease 240 mayalso be designed to facilitate a controlled deformation of the retainingextension 228. Preferably, the crease 240 is provided by a relativelysharp corner. Now, for metal ferrules that are machined, such asstainless steel ferrules in the exemplary embodiments herein, there isno true 90° corner. Rather, a 90° or sharp corner would be morecorrectly thought of as a tight radius corner, for example a radius inthe range of approximately 0.001 inch to approximately 0.015 inch, morepreferably approximately 0.002 inch to approximately 0.01 inch, andstill more preferred in the range of approximately 0.003 inch toapproximately 0.005 inch. Such a tight or sharp corner will provide ahinge-like action of the crease 240 that will help assure a forwardbending deformation that will not stress the back ferrule cartridgefeature 206 and will produce an acute post-cartridging angle for theangle α. The crease 240 may be designed in concert with the web 220flexibility to achieve the desired deformation, ease of cartridging, androbustness of the ferrule cartridge 200.

Even though there is a plastic deformation of the retaining extension228 the cartridging process may still exhibit a snap together feel oreffect if so desired but such is not required.

A near right angle α as set forth herein prior to cartridging allows thecartridging process to occur such that the retaining extension 228 doesnot encounter a buckling resistance of the web 220 or the retainingextension 228. This reduces the opportunity for the cartridging processto generate burrs or ring chips or other metal debris from the surfaceof the back ferrule 204, particularly along the surface of the cartridgefeature 206.

Note that as in the embodiments hereinabove, the recess 234 may bedimensioned to allow for a Type 1, 2 or 3 cartridge connections,especially a Type 3 that allows the ferrules to be cartridged togetherwithout significant radial or axial load between the ferrules in thesubassembly condition.

FIGS. 46-49 illustrate the ferrule cartridge 200 embodiment of FIGS.42-45 (with the front ferrule of FIG. 42A) with an embodiment of aconduit fitting with a conduit end T, from finger-tight assembly througha typical 1⅞ (1.875) turns pull-up past finger-tight. In an embodiment,a first fitting component may be a male-type conduit fitting 250 thatincludes a male threaded body 252, and a second fitting component may bea female threaded nut 254 that is joinable with the body by a threadedconnection 256 (as is convention, the body is the fitting component thatreceives the end of the conduit). In the finger-tight position (FIGS. 46and 47) a ferrule drive surface 254 a of the nut touches the back end ofthe back ferrule 204, the forward portion 208 of the back ferruletouches the camming surface 218 of the front ferrule 202, and a forwardportion near the front end 212 of the front ferrule touches the bodytapered camming surface 258 that presents a frustoconical camming mouthat the rearward portion of the front ferrule 202, as is known. In anembodiment, the body 252 may be part of a union as shown, oralternatively the body 252 may be provided in another of manyconfiguration such as but not limited to a tee, an elbow, a cross, aswell as female-type fitting configurations. The finger-tight position isa reference position for pull-up in which the nut 254 and the body 252are axially displaced (also known as relative axial stroke past thefinger-tight position) by relative rotation with respect to each otherfor a prescribed number of turns (including partial turns as needed). Acommon but not required stroke for complete initial (first time) pull-upis 1¼ (1.25) turns past finger-tight position. Pull-up (FIG. 48A)involves the back ferrule 204 being axially driven by the nut 254against the camming surface 218 of the front ferrule 202, which drivesthe front ferrule 202 against the camming surface 258 of the body. Thefront ferrule 202 tapered outer wall 214 forms a fluid-tight sealagainst the body camming surface 258; the front ferrule also has aninternal bore delimited by a wall that is compressed against and sealsthe outer surface of the conduit T. The forward portion of the backferrule 204 is radially compressed against the conduit outer surface byaction of the camming surface 218 of the front ferrule, which causes theback ferrule to grip the conduit and may optionally also provide a sealagainst the conduit surface. The rear portion of the back ferrule tendsto rotate radially outwardly away from the conduit surface, althoughother ferrule designs may deform differently. Also, the inward radialcompression (arrow RC) of the forward portion 208 of the back ferrule204, along with an optional radially outward rotation or expansion(arrow RO) of the front ferrule 202, results in disengagement or releaseof the back ferrule 204 from the retaining structure R (FIG. 42).

Note that the retaining structure R does not interfere with or changethe form, fit and function of the ferrules, especially during thepull-up process. In some embodiments, such as shown in FIGS. 48 and 49,a portion of the member 220 may make contact with a surface of the backferrule 204, but this contact does not impede normal ferrule functionduring pull-up. In an exemplary embodiment, this contact may not be madeat 1.25 turns past finger-tight position, and may not occur until 1.5turns or more which may correspond to five to ten remakes, with earliercontact (e.g., at 1.25 turns past finger tight) being more likely tooccur for thick wall conduit.

In other embodiments, according to an inventive aspect of the presentapplication, the ferrules may be configured such that engagement betweenthe front ferrule web 220 and the rear ferrule 204 during the pull-upprocess, as described above, coincides with relative axial displacementof the threaded fitting components that may be associated with thenumber of complete and/or partial turns past the finger tight positionfor complete fitting pull-up, during initial fitting installation,and/or for one or more remakes, similar to the embodiment of FIGS. 36and 37 described in greater detail above. In such an embodiment, thefront ferrule web 220 may function as a stroke limiting extension orstroke resisting member, similar to the stroke limiting extension 310′of the fitting of FIGS. 36 and 37. Accordingly, the retaining member 220may be used to allow pull-up by torque, as an alternative to pull-up byturns, using a prescribed or predetermined torque for relative rotationof the body and the nut that will advance the body and nut axiallytogether to the prescribed pull-up stroke. The retaining member 220 mayhave an end surface 229 (for example, defined by the retaining extension228) that contacts a bearing surface 260 of the back ferrule 204, forexample on a back ferrule flange 262 at the prescribed pull-up strokepast the finger-tight position as shown in FIG. 48. The retaining memberor stroke resisting end surface and the back ferrule bearing surface maybe substantially radially aligned, such that at least a majority of thestroke resisting end surface is radially aligned with at least amajority of the back ferrule bearing surface. This contact between theretaining member 220 and the back ferrule 204 produces an axial load orcompression on the retaining member 220 during relative rotation of thebody and the nut. (Note that there may also be radial loads applied tothe retaining member 220.) The axial compression or load on theretaining member 220 produces or is accompanied by an increase in thetorque required to continue to pull-up the fitting (i.e. continue toapply torque for relative rotation of the body and the nut), and thistorque increase is greater than would be presented if the contact andaxial load or compression did not occur. The retaining member 220plastically axially deforms so that the fitting may be remade using aprescribed torque or turns. Initial pull-up and remakes may optionallybe carried out using the same prescribed torque or different torquevalues. FIG. 49 illustrates the fitting 100 after one or more remakes inwhich further plastic deformation of the retaining member 220 allows thefitting to be remade for one or more remakes to effect conduit grip andseal.

Depending on the expected relative axial movement of the front ferruleretaining member 220 and the back ferrule flange 262 during pull-up, thefront ferrule retaining member may be provided with an axial length thatis selected to provide engagement between the retaining member endsurface and the back ferrule flange bearing surface at a predeterminedaxial advance of the fitting body and nut during pull-up (e.g., at least1¼ turns past a finger tight position). FIG. 49A illustrates anexemplary ferrule 202″ similar to the ferrule 202 of FIG. 42A, exceptwith a retaining member 220″ having an axially extended end portion229″, extending beyond the retaining extension 228″ and sized forengagement between the retaining member end portion 240″ and the backferrule flange bearing surface at a predetermined axial advance of thefitting body and nut during pull-up. According to another inventiveaspect of the present application, an axially extending end portion 229″may additionally or alternatively be provided for additional strengthand rigidity of the retaining member 220″.

Contact between the retaining member 220 of the front ferrule 202 andthe rear portion of the back ferrule 204, whether or not such contact isused to facilitate pull-up by torque, as described above, may in somecases, for example, for thick wall tubing or conduit T, have the effectof an increased expansion of the rearward portion 216 of the frontferrule. This expansion may provide increased load on the cammingsurface 258 of the body 252 (FIG. 46), particularly in the outboardportion of the body camming surface 258. A somewhat exaggerated exampleof this is shown in FIGS. 49 and 56A. According to a separate inventiveconcept of the present application, we have found that the load at therear or outboard portion the body camming surface may be reduced byproviding a front ferrule having an outer wall surface that continuouslydeclines in angle from a forward portion that initially engages the bodycamming surface during pull-up, toward a rear portion axially alignedwith an outboard portion of the body camming surface. This reduced loadat the outboard portion the body camming surface may reduce outwardexpansion of the body, which may occur in some fitting embodiments,including, for example, fittings utilizing a front ferrule with acartridge feature that contacts a surface of the rear ferrule duringpull-up or remake (e.g., the fitting of FIGS. 42-49), as describedabove.

Accordingly, the present application also contemplates the use of afront ferrule (both in the fittings described herein and in variousother fittings utilizing one or more conduit gripping devices) having anouter wall with a forward portion oriented for initial engagement with afitting body camming surface during pull-up, and a rearward extendingcontoured portion having a continuous rearward declining angle withrespect to the forward portion. As used herein, surfaces with a“continuous rearward declining angle” are intended to include surfacesfor which longitudinal tangents to points along the length of thesurface continuously (although not necessarily at a constant rate)decline in angle from the front end of the contoured surface to the rearend of the contoured surface. The continuous rearward declining angle ofthe contoured portion of the front ferrule outer wall may reduce oreliminate radial load forces on the rear or outboard portion of the bodycamming surface by effectively removing radially outer material from therear portion of the ferrule, while maintaining sufficient materialtoward the front of the ferrule for sealing engagement with the cammingsurface and to limit outward radial expansion of the ferrule.

Additionally, a contoured ferrule surface having a continuous rearwarddeclining angle may be provided with a steeper (i.e., having a greaterangle) front end, as compared to the straight frustoconical outer wallsurface of a conventional ferrule, for example, to maintain increasedmaterial at a middle portion of the front ferrule to stiffen the frontferrule for flexing at this middle portion during pull-up, and/or tolimit axial advance of the front ferrule into the body camming mouthduring pull-up. This initially steeper contoured surface may provide agreater radial spring load on the nose of the back ferrule, enhancingthe tube gripping function of the back ferrule. In one example, thefront end of the contoured surface may have a tangent angle that isgreater than a conventional frustoconical ferrule wall angle (e.g.,greater than about 15°) but less than or equal to the angle of thetapered body camming surface (e.g., less than or equal to about 20°, forexample, about 17°), thereby providing an enlarged middle portion of theferrule. The contoured surface may be oriented such that a portionrearward of some point in the middle portion is shallower than theconventional frustoconical ferrule wall angle, thereby effectivelyremoving material from the rear portion of the ferrule.

By limiting the body camming surface engaging portion of the ferruleouter wall to a tangent angle no greater than the body camming surface,and by providing a contoured surface with a continuous rearwarddeclining angle, engagement between the front end of the ferrule outerwall contoured surface and the body camming surface may be maintainedthroughout fitting pull-up. In other words, once fitting pull-upproduces engagement between the front end of the ferrule outer wallcontoured surface and the body camming surface, further pull-up will notcause the ferrule outer wall surface to “rock” against the body cammingsurface, and the front end of the ferrule outer wall contoured surfacewill not separate or disengage from the body camming surface.

Many different types of contoured surfaces may be utilized to provide acontinuous rearward declining angle. In one embodiment, the contouredsurface may include a convex curvature, forming a frustoellipticaltapered outer wall surface. Other complex contoured surfaces mayadditionally or alternatively be utilized.

With reference to FIGS. 50-56, in an alternative embodiment, a frontferrule 260 for the ferrule cartridge 200 of FIGS. 42-49 may be but neednot be the same as the front ferrule 202 with the modification of aconvex outer wall surface 262 (convex as viewed in longitudinalcross-section) that extends from a forward portion 264 of the frontferrule, optionally to the front end 266 of the front ferrule, towardsthe rearward portion 268 of the front ferrule, optionally to the flange244 at the forward surface 242.

We use like reference numerals for like features with the embodiment ofFIGS. 42-49. Operation of the ferrule cartridge 200 and the conduitfitting 250 with the alternative front ferrule 260 may be the same asdescribed above for the embodiment of FIGS. 42-49. The convex outer wallsurface 262 may have a radius R1 as viewed in longitudinal cross-section(FIG. 50 for example) or may be a different convex profile or geometry,for example may comprise a combination of radii and straight portions.The convex surface 262 is formed in the front ferrule 260 to be presentin an unstressed condition. The convex surface 262 may be used in someembodiments to position the radial load forces (represented by arrow Gin FIG. 56) that form the fluid-tight body seal between the frontferrule 260 and the body camming surface 258 to be more axiallylocalized in an inner portion of the body camming surface 258.

The combination of the convex outer wall surface 262 of the frontferrule with the cartridge feature or member 220 on the back of thefront ferrule presents an embodiment of a separate inventive concept.The addition of the convex outer wall surface 262 to the front ferrule260, as shown in the example of FIG. 50, may reduce the load G at therear or outboard portion the body camming surface 258 and hence reduceoutward expansion of the body 252, which may be present if the cartridgefeature 220 of the front ferrule 260 contacts a surface of the rearferrule. For example, by comparing FIGS. 49 and 56 it will be observedthat the convex outer wall surface 262 (FIG. 56) restrains the axialoutboard advance of the front ferrule 260 into the camming mouth of thebody 252 against the camming surface 258. This helps axially distributeor localize the load G to a more inner portion of the camming surface258 (FIG. 56) as contrasted with FIGS. 49 and 56A where the load G′influences to a greater extent the outboard portion of the cammingsurface 258.

Alternatively, the convex (or otherwise contoured to have a continuousrearward declining angle) outer wall surface need not fully extendbetween the forward surface and the front end of the front ferrule. Forexample, the convex outer wall surface may only define a portion of thesurface that extends between the flange and the front end of the frontferrule. The convex outer wall surface in such a case, for example, mayblend to a frustoconical taper or transition along the forward portionor front end of the front ferrule. FIG. 57 illustrates an exemplaryfront ferrule 1260 having a forward frustoconical taper portion 1265extending rearward from the nose 1266 of the ferrule, and a convex orfrustoelliptical contoured portion 1267 (distinct from the radiuscontour of the ferrule nose) extending rearward from a rear end of thefrustoconical taper portion 1265. The forward frustoconical portion 1265may provide for an extended forward region of radial load on the fittingbody camming surface, which may, for example, form an enhanced gas seal.The frustoconical portion 1265 is preferably disposed at an angle thatis greater than or equal to the tangent angle of the front end of thefrustoelliptical contoured portion 1267, such that when the front end ofthe frustoelliptical contoured portion 1267 engages the camming surfaceduring pull-up, engagement is maintained at least at the front end ofthe frustoelliptical contoured portion 1267 during further pull-up. As aresult, there is no rocking motion of the ferrule outer wall against thecamming surface and about the front end of the frustoellipticalcontoured portion 1267.

As another example, a convex or frustoelliptical outer wall surface of afront ferrule may additionally or alternatively blend to a frustoconicaltaper or transition along the rearward portion or rear end of the frontferrule. FIG. 58 illustrates another exemplary front ferrule 2260 havinga rear frustoconical taper portion 2269 extending rearward from a convexor frustoelliptical contoured portion 2267 of the ferrule outer wall.The frustoelliptical contoured portion 2267 may extend rearward directlyfrom the nose 2266 of the ferrule 2260, like the ferrule of FIG. 50, orfrom a forward frustoconical taper portion 2265 that extends from thenose, like the ferrule of FIG. 57. The rear frustoconical portion 2269may, for example, be axially disposed on a portion of the ferrule thatwill remain outside the camming mouth of the body after fitting pull-up.

While FIGS. 50-56 illustrate a convex outer wall surface on a frontferrule having an axially forward bending retaining member forcartridging, the convex (or otherwise contoured for a continuousrearward declining angle) outer wall surface may additionally oralternatively be provided on other cartridging front ferrules, as wellas non-cartridging ferrules (including single ferrule and other multipleferrule fitting embodiments). FIGS. 59-61 illustrate exemplarycartridging and non-cartridging ferrules having a convex orfrustoelliptical outer wall surface, in accordance with inventiveaspects of the present application.

According to still another inventive aspect of the present application,contact and/or radial loads between the front ferrule and an outboardportion of the body camming mouth may be further minimized or eliminated(in addition to or instead of use of the contoured outer wall ferrulesurfaces described above) by providing the front ferrule with a rearflanged portion sized to engage an interior surface of the fitting nut,upon radial expansion of the front ferrule, and before the front ferrulecontacts or applies a radial load to the outboard portion of the bodycamming mouth. For example, the front ferrules of at least FIGS. 36, 39,42A, 45, 50, 57, 58, 60, and 61 include rear flange portions that may besized to engage an interior surface of the fitting nut, upon radialexpansion of the front ferrule, and before the front ferrule contacts orapplies a radial load to the outboard portion of the body camming mouth.

The inventive aspects have been described with reference to theexemplary embodiments. Modification and alterations will occur to othersupon a reading and understanding of this specification. It is intendedto include all such modifications and alterations insofar as they comewithin the scope of the appended claims or the equivalents thereof.

1. A fitting for conduits having a reference axis, comprising: a first threaded fitting component; a conduit gripping device receivable within the first threaded fitting component; a second threaded fitting component that threadably joins with the first threaded fitting component to produce relative axial stroke between the first threaded fitting component and the second threaded fitting component, wherein when the fitting is pulled-up on a conduit the first fitting component and the second fitting component can be joined together to a first relative axial position of the first and second fitting components to effect conduit grip and seal by the conduit gripping device at the first relative axial position; and a stroke resisting member having a first axial length, the stroke resisting member being disposed between a threaded portion of the first fitting component and a radially extending portion of the second fitting component; wherein the stroke resisting member is axially engaged by the radially extending portion of the second fitting component when the first and second fitting components are joined together to the first relative axial position, the stroke resisting member resisting additional axial stroke of the first and second fitting components, such that a tightening torque beyond the first relative axial position is increased by the axial engagement; and wherein the stroke resisting member is plastically compressed to a second axial length smaller than the first axial length when the first and second fitting components are joined together to a second relative axial position advanced beyond the first relative axial position.
 2. The fitting of claim 1, wherein the stroke resisting member is integral with the first fitting component.
 3. The fitting of claim 1, wherein the stroke resisting member is non-integral with the first fitting component.
 4. The fitting of claim 1, wherein the stroke resisting member is assembled with the first fitting component, such that the first fitting component and the stroke resisting member are retained together as a discontinuous preassembly.
 5. The fitting of claim 1, wherein the stroke resisting member is cartridged with the first fitting component.
 6. The fitting of claim 1, wherein the stroke resisting member is freely rotatable with respect to the first fitting component prior to axial engagement by the radially extending portion of the second fitting component when the first and second fitting components are joined together to the first relative axial position.
 7. The fitting of claim 1, wherein the first fitting component comprises a female threaded nut.
 8. The fitting of claim 1, wherein the stroke resisting member is axially fixed to the female threaded nut.
 9. The fitting of claim 1, wherein the stroke resisting member comprises a proximal ring portion having a first radial thickness, a distal ring portion having a second radial thickness, a first wall portion having a third radial thickness smaller than the first radial thickness and extending axially from the proximal ring toward the distal ring, a second wall portion having a fourth radial thickness smaller than the second radial thickness and extending axially from the distal ring toward the proximal ring, and a web connecting the first and second wall portions, the web being angled with respect to each of the first and second wall portions to define a hinge portion.
 10. The fitting of claim 9, wherein the proximal ring portion is integral with the first fitting component.
 11. The fitting of claim 9, wherein the proximal ring portion includes a radially inward extending protrusion for cartridging engagement with a threaded fitting component.
 12. The fitting of claim 9, wherein the distal ring portion comprises a radially extending bearing surface for engaging the radially extending portion of the second fitting component.
 13. The fitting of claim 9, wherein the first wall portion extends from an inner radial portion of the proximal ring.
 14. The fitting of claim 13, wherein the second wall portion extends from an inner radial portion of the distal ring.
 15. The fitting of claim 9, wherein the first wall portion has a first outer diameter and the second wall portion has a second outer diameter different from the first outer diameter.
 16. The fitting of claim 9, wherein the first wall portion has a first inner diameter and the second wall portion has a second inner diameter different from the first inner diameter.
 17. The fitting of claim 9, wherein the web includes a portion that is generally V-shaped when viewed in longitudinal cross-section.
 18. The fitting of claim 9, wherein the hinge portion of the web is entirely radially outward of the first and second wall portions.
 19. The fitting of claim 9, wherein the web plastically deforms under axial compression, thereby reducing the axial length of the stroke resisting member.
 20. The fitting of claim 9, wherein the web buckles when an axial load is applied to one of the proximal ring portion and the distal ring portion, thereby reducing the axial length of the stroke resisting member. 21-143. (canceled) 